State of the Discussion

I think both smart and clever are secondary terms, the base meaning of smart was painful or cutting (Ouch, that smarts!), while cleaver was probably to split up or divide (hence meat cleaver), which constrasts with dull, so both point out the ability to break things down into smaller parts. I imagine in a closed village society, being intelligent could be disfavored a bit, because it would be disruptive.

How fascinating, I have just looked up smart in the OED and the main usage for e.g. clothes seems to be "Attractively neat and stylish, relatively formal". It's true, I can imagine if someone asks what you think of an outfit, and you don't know them all that well and want to reassure them you might say "very smart", but generally speaking most people I know would use it in the way following, which is "Fashionable, elegant, sophisticated; belonging to or associated with fashionable or high society." Like so much else in UK English, it looks like it might be more class-coded than I realised.
And just before those two usages, despite what I have said before, the following: "Clever, intelligent, knowledgeable; capable, adept; quick at learning, responding intelligently to a situation, etc.; astute, shrewd; (of an action) characterized by cleverness or astuteness." In my experience this usage is rare here, although possibly more common as a result of American movies, literature etc.

Interestingly, none of you seem to be talking about "intelligent" as opposed to the other two words. It's hard for me to get my head round, because as I say "smart" is not often used that way here - except in the case of something like "street smarts".
I would say that most people in the UK who think about such things would think of "clever" and "intelligent" as almost synonyms, and that both (while frequently connected with education and knowledge) could possibly be present in exceptional people who have had almost no access to either, but who have what I think nous is calling "wits". And then, there are people who are particularly gifted in certain ways, for example with an innate understanding of mechanical (or spatial) processes. At least, that's how I understand the usual usage in the UK, but I may be extrapolating from my own and my (i.e. of age, education, social class) cohort's conception. nous's definitions @05.56 strike me more as something to do with personality, or turn of mind, rather than actual intellectual ability.
So maybe all our understanding of these terms is idiosyncratic....how fascinating this stuff is.

For me, the difference between "smart" and "clever" is mostly about scale. Smart operates on a larger scale than clever. The phrase "too clever for their own good" is illustrative. In computer programming, it usually means things like really obscure code that exploits some odd aspect of the programming language to make this routine run faster today, but that will turn out to be a maintenance nightmare in months/years to come.

I've never been to either the Hearst Castle or the Carnegie Mansion in NYC. Are they really as dismally dark as they look in the photographs? Or is that an artifact of no-flash policies and old slow films?
Or alternatively, has four decades of living in Colorado where almost everywhere has huge expanses of glass spoiled me?

Trump is a vulgar clown, and his residence in Trump Tower reflects that. I don't care. Whatever floats his boat.
But that kind of garish, ostentatious display doesn't belong in one of the the physical seats of our national government.[Not to mention, of course, an historic building.]
God knows, I agree with that, and I have to admit that many of my tastes and attitudes are pretty snobbish. The Jantelagen aspect is also an interesting point. I realise I've never had any problem with mocking or criticising Ubu's taste at e.g. Mar a Lago, possibly because he's rich and fair game. I think it was the "Regional Car Dealership" thing that worried me.

I couldn't shake the feeling that sneering at someone's ignorance, particularly in the matter of taste, immediately marks one out as a member of the kind of "elites" that have understandably caused such vitriolic resentment.
I hear you. And, as someone who can be a snob about a number of things, I try not to make fun of or look down on other people's taste. Whatever it is. With, you know, varying degrees of success. But I do try to avoid it, mostly because it's rude, but also because it feeds the dynamic you describe here.
All of that said, we're not talking about somebody's personal taste and how that is expressed in their own home or appearance.
It's the freaking White House, home of one of the three branches of the US government and residence of it's chief executive.
Trump is a vulgar clown, and his residence in Trump Tower reflects that. I don't care. Whatever floats his boat.
But that kind of garish, ostentatious display doesn't belong in one of the the physical seats of our national government.

Well, the tone I got from that McMansion piece was how RCDC was a corruption of the thought-out sources it munges together that simply juxtaposes them without creating or defining any relationship beyond proximitry. Appropriation, if you will. What mockery there is comes from the analysis of the failure of the idea. Is the mockery undeserved? Is criticizing the asthetic taste of the President of These United States punching down?

Other than a "this looks like pictures I've seen" sort of observation, I really don't have any room to criticize decorating choices. My wife and I always said that our style was "graduate students who occasionally had some found money" crossed with "people actually live in this room".
Earlier this year I got tired of having to climb out of the futon and bought living room furniture that I sat "on" rather than "in". It felt really strange to go shopping for furniture without my wife. Plain because I'm a graduate student at heart. Inexpensive because, well, I might only realistically need to get ten years out of it. Three pieces so that I can separate the granddaughters as needed to avoid "Grandpa, she's poking me!" Everything else in this picture has a back story.

I enjoyed Cheez Whiz's link, which was interesting and informative. I laughed at Regional Car Dealership Rococo (it's perfect!), but it still left me obscurely uncomfortable.
Tempting and enjoyable as it can be to mock Trump, and his absurd and transparent pretensions, I couldn't shake the feeling that sneering at someone's ignorance, particularly in the matter of taste, immediately marks one out as a member of the kind of "elites" that have understandably caused such vitriolic resentment. A sense of superiority, no matter how easily explained, always makes me question how justifiable such feelings are/can be.
I'm not preaching here - I've had to work out why I ended up feeling so uncomfortable after reading it and laughing, and this is just my first stab at trying to account for that feeling.

The woman who had that McMansion hell website has a Patreon, and she recently posted a dive into what she calls Regional Car Dealership Roccoco, her term for the Trump architectural esthetic.
https://www.patreon.com/posts/mcmansionization-126873692

Whenever I read anything by Yarvin, I feel like I'm back in college listening to some zero-social-skill rando who overdosed on Ayn Rand in high school holding forth at 2 in the morning after doing enough bong hits to anaesthetize an elephant.

Napoleon III was more into kitsch art afaik.
https://en.wikipedia.org/wiki/The_Birth_of_Venus_(Cabanel)
The reproductions I can find on the net all lack the correct (and aesthetically sickening) ivory/pink shade and thus do not give the proper impression of the original.
This https://en.wikipedia.org/wiki/Napoleon_as_Mars_the_Peacemaker on the other hand is more on the ridiculous side but not necessarily bad taste or low quality art (like the gilded plastic statue of His Orangeness).
The precedent would be https://commons.wikimedia.org/wiki/Category:Claudius_as_Jupiter_(Pio_Clementino_Museum)#/media/File:Claudius_(Vatikanische_Museen).jpg
Again not low quality art but the discrepancy between the real person and the image (Claudius being widely known for having a walking disability, so the proper deity would have been Hephaistos)

Thank your lucky stars that Strump hasn't razed the White House and replaced it with a garish casino.
Yet. Gotta save a few big projects for the third term.

I have to admit that everytime these inland forages of oceans come up, I have to struggle whether they are spelled with a u or an o in English (btw, the same with disaster vs. desaster)*.
No excuse for Persion though.
For that matter no one noticed that feasibility got misspelled feasability in the title of my PhD thesis until after it got approved and published (electronically). Well, at least it is easier to find that way.
*in German it is Golf and Desaster

It isn't just that the design is tasteless. It's that the execution is so poor. I think "sloppy" is the word I'm looking for.
It's like no competent craftsmen could be found to do it. Although most likely nobody looked, if they had there might have been a derth of people willing to work under any terms except cash in advance. A poor reputation can do that.

"I know fully well how vulgar that is and I did it on purpose!'.
Well, we don't have to consider that. Trump has no clue how vulgar it is.

There was very bad taste in the past too (even by the different aestethic standards of the day). There is a degree of preservation bias but also a "where to look" one.
Where one still can find lots of - in my opinion - aesthetic abominations is in churches with Roman catholic ones being the main culprits (and there churches dedicated to Mary leading the charge).
Orthodox churches also do lots of gilding but imo it's not that 'in your face'.
In the case of His Orangeness and his role models round the Persion Golf the lack of tast is imo to a degree program. The absence of any kind of subtlety is the very point.
It's not the amount of precious materials that makes bad taste but the lack of subtlety.
In the past there existed an art of showing off aimed at experts and equals. Those whose opinion counted would notice and that's what counted.
These days that knowledge is there no more in either the target audience nor the show-off-ers themselves.
About the only thing missing is glaring price tags put everywhere to rub it in.
And then there is of course the cliche of "the kind of shabbiness only the very rich can afford", putting pride in the very expensive stuff looking like crap deliberately while reminding everyone HOW expensive it was.*
Apart from that, the vulgarian ultra-rich seem to have lost the art of decadence with style.
They would not 'get' Trimalchio (or even see him as too intellectual).
* Remembering "The People vs. Larry Flynt" I wonder, whether the vulgarity of his mansion (the real one iirc shown at the end of the film) was him lacking taste or a bold statement of 'I know fully well how vulgar that is and I did it on purpose!'.