I can't, and won't, even try to explain attraction. Hell, I scratch my own damn head at some of the things that catch my eye every once in a while.
I'd say I'm "okay" looking, I get looks, so I guess I am not hideous.
I think I get more interest because of my "swagger", if that's what it is. I just don't care about guys, so they tend to have this odd compulsion to talk to me. (I mean this in the sense of not looking for anyone at the moment, and just enjoying my own skin.)
Ramble aside, I think it just boils down to personality and in some instances maturity levels.
You can be the most beautiful person in the world or the hunchback of Notre Dame, but if you have a fucked up attitude or are so unhappy with yourself that you leave fume trails, don't expect people to be banging down your door.
I have heard some of my attractive guy friends say things about a woman's body, and then end it with "but she has a fucked up grill/eye/whatever". Those are the players.
I guess it just really boils down to the individual cases and what exactly they are out looking for.
I dunno. this probably didn't even make any sense. low blood sugar and sleepy don't mix with keyboards.