Apart from nipples (which we know from the breastfeeding debacle are verboten on facebook), several of them are naked bar their pants/bikini bottoms. And of those that are wearing slightly more, most of them are pouting at the camera in the manner of a Zoo cover. I just find it hugely depressing. These are intelligent young women, doing their A levels or at university.
When I was that age, we were determined that we wouldn't be seen as sex objects and would have been appalled to have photos like that of us around, much less put it up as a profile picture for the whole world to leer at. And now it seems like it's all a bit of a laugh. No wonder sexism isn't taken seriously.