I don't know the american Guggenheim, but the Bilbao one, by Gehry, is the most amazing single man made thing I have ever seen. PC probably thinks it is a whitlow on the finger of a not very much loved Basque city.
What does it say on the tin, I ask myself, "upper class twit" maybe?
I have a lot more time for his sister who does seem capable of talking to other people - well sportspeople anyway - like a normal human being. She would make a far better fist of being the monarch. ANd would have the sense to know that no, it is not appropriate for him to try to influence ministers. Which is presumably what he was up to. He is not an ordinary voter. (And the protocol is that you write to your MP and they take things up with ministers, rather than contact them directly.)
I think in this case the att. general probably means that he hopes PC has copped on that this kind of behaviour unbecoming and inappropriate in the heir to the throne.