Nude scenes

I can't answer the British part but in France nudity alone is not censored as long as it's not directly related to sex acts. You can show naughty bits on prime time television without trouble. And that includes male parts. I'd say you see less of it for the same reason good looking actresses are more sought after than good looking actors.

Why do French movies have more female nude while English films have male nude instead?

As an English person I can't say I've noticed that we show male nudity more than female... I think in general the whole of Europe is pretty relaxed about nudity.

As for serving a purpose... well I think the style of European cinema is more inclined to be natural about things. Nudity doesn't have to serve a purpose, if two people are swimming in a lake naked together then a natural camera angle is what you'll get, nudity and all. There's no purposely zooming into the good stuff, or cutting away before a boob or bum appears. It's just as if the camera has been placed there and the characters do their thing, what you see is what naturally appears.

I think that when Americans (or anyone in fact) makes the point "Nudity doesn't serve a purpose" in a film it really shows the difference in viewpoints on the human body. For me it's not about purpose, it's just the evolution to a more natural cinema, which is a style/feel I really enjoy. Take someone like Michael Bay, he may not show bare flesh, but his style is far more gratuitous/unnecessary than simply seeing a penis flop about on screen.

In general, there's more nude scenes in European films than Hollywood, sometimes it serves no purpose.

As an American who mostly has to put up with Hollyweird and it's strange way of dealing with nudity I was pleasantly surprised to see the actress's butt shown. Usually over here we'll get a quick peek at some breasts followed up by man ass. Our ratings system run by the super secret and corrupt MPAA makes no sense. There are a slew of dick shots in American movies/tv shows and almost never an appearance of an actress displaying vulva. American shows are afraid of female bodies and anything involving vaginas.

I agree with some of the previous posters. When the nudity is natural and the camera angle and the scene just seem to occur in a realistic way it only adds to the authenticity of the movie, and in this movie it did that.