aw, I don't mind reading long replies
Well, IMHO those expectations stem from what we see on a daily basis, in movies, ads, shops, magazines etc.
I've once seen a TED talk about the self-checking most women do all the time...It was something like in 20 minutes, they unconsciously check themselves 5 times (does my shirt stick out? does my belly look fat in these jeans? did my bag pull down my shirt too far? did I smear my make up? etc).