Yes, I wondered this as well. If it's the same survey that a PP posted above, it asks whom you think 'looks the best' rather than which do you 'most fancy'.
After the age of 31, the women also all said that men younger than them 'look the best', albeit choosing a range of younger-aged pictures (I assume that's how they did it) rather than just the ones aged around 22.
If you asked most women who 'looks the best' and showed them pictures of George Clooney, Tom Hiddleston, David Gandy, Kev from next door, Phil who works in the local shop - or indeed their own DHs - the vast majority would laugh and say obviously the famous ones. That doesn't mean that they don't find their own DH very attractive for everything he is to them or that they would instantly dump him in favour of a Hollywood actor, though.
Germaine Greer released a book a long time ago called 'The Beautiful Boy', which featured photos of young juvenile males (sometimes partially clothed) and focused heavily on how nice-looking/attractive/beautiful they were. That was the whole premise of the (creepy) book.
I think it was very ill-advised of her indeed, and had the sexes been reversed, I don't think a male author would have got away with it for a second (and rightly not imho). It still makes me look at her in a different light, in spite of all of the wonderful insightful things that she's said, written and done over all these years.
I think it's very important to make the distinction between a young adult and an actual child. If GG had released a photo book of young men aged, say, 18-25, it would still have been creepy, but nowhere near as questionable.