You can not understand this sort of thing if you model humans as idealized Vulcans. You have to understand that sex and nudity and such are all tied up not just with our forebrain, but with our irrational hindbrains, and we don't get to choose what "programs" those are running. I'm not saying I have a really easy answer, just that being mystified by these sorts of things is an indication that you're running on the wrong model of human minds. These issues are real, and the nudity is merely a player on a complicated game board of deep human currents of sex, power, hierarchy, and public morality, its need to be enforced, and it's need to be seen being enforced (important not to model those as the same thing!), playing out in a complicated iterated group social game.
Further, it's worth pointing out that the people painting the nudity were not Vulcans neutrally painting "just what reality is" either. The painters set out to push certain buttons with those paintings, and the fact that people react is a measure of the fact they succeed. It should hardly be a mystery that people have further responses to the fact certain buttons are being pushed; indeed, it would be a mystery if they did just consider it no different than a painting of a bowl of fruit.
"sex and nudity and such are all tied up not just with our forebrain, but with our irrational hindbrains, and we don't get to choose what «programs» those are running"
We can, however, train ourselves to pass more control on our forebrain and, like you mentioned ("painters set out to push certain buttons with those paintings"), those paintings were a very important tool to measure the success of that. When there is this dignitary empowered to act on collective behalf, it's only comforting to find out that he holds enough self-control to act cool and rational, that he is competent enough to deal with whatever social play, including the basic instinct attempts, without compromising whatever public business he's out to solve. Given the context, this pampering only unsettles me!
We're talking about pieces of art that have been around for centuries - and about people of power who are in the same positions as those that commissionned this pieces before them.
Who has the most thoughtful, the "right" "model of human minds" between those who commissionned these works, those who produced them and those who veiled them today?
You seem to be asking questions about judging value or morality. I'm only talking about understanding.
The original article didn't exactly come out and say that they found the whole thing mystifying, but I've seen enough similar things that it seemed relevant, and I do think that's the general tone.
People in that same position of power also killed rather a lot of middle easterners in the Crusades. I don't think we should use all their choices as a model for modern ones.
Besides, the same type of nude art works, were produced long before (even in prehistoric times), east, south, north, and west of the Mediterranean sea.
Context matters too, I suspect some of those works when commissioned were meant to be enjoyed semi-privately, in someone's mansion or palace. Now they're placed in a public building behind people being photographed.
By all means, let us ignore the herd of elephants stomping through the room.
This is all about the strange and disastrous new European fear of offending Those Who Must Not Be Offended. In this case a visiting Iranian head of state, but we see this stuff played out all over Europe every day, from this level and all the way down to minor, personal encounters.
It's just as much the puritanical Christians and the feelings of Progressives that are demanding these coverups. It is not muslims, it is the blowback against freedom of speech by a number of groups who feel that they have a right not to be offended, and that their dogmatism is the one true way.
It's not a surprise, these things are cyclical, and global culture went through nearly 50 years of expanding tolerance - The drug use of the 60s and 70s, glorification of teenage rebellion in 80s and 90s, and the tech disruption of the aughts. We're seeing a resurgence of spirituality, in much the same way we've seen it before[1]. Not all of it is explicitly religious, some of it is just indistinguishable in it's goals.
I don't think it has anything to do with spirituality or even with religion.
There seems to be a certain alpha male - or at least alpha authoritarian - model of power which is rooted in a pretence of stern, serious, and disciplined public morality combined with private self-indulgence.
When you have naked boobies on display in public buildings, that model of pretended integrity starts to break down. Boobies and naked bodies - especially female bodies - are fundamentally antithetical to the immensely serious business of public alpha moral posturing. They're strictly for private off-the-record consumption only.
Non-authoritarians don't care about keeping up appearances in this way. But authoritarians and narcissists most certainly do.
There was a rather good cartoon in Private Eye this month (unforately not online as far as I can google) where Adam and Eve (from the last judgement mentioned in the OP) are captioned saying "It's worse that we thought - we're being slammed on Twitter"
Further, it's worth pointing out that the people painting the nudity were not Vulcans neutrally painting "just what reality is" either. The painters set out to push certain buttons with those paintings, and the fact that people react is a measure of the fact they succeed. It should hardly be a mystery that people have further responses to the fact certain buttons are being pushed; indeed, it would be a mystery if they did just consider it no different than a painting of a bowl of fruit.