This is a sarcastic counter against people with ridiculously high standards for what are actually quite beautiful women.
Usually it is in response to people who have oddly specific criticisms of a woman, such as thighs being too wide, or shoulders too wide or any of that stuff, who need a reminder that they're not Brad Pitt.
Some Dude: Hey man, check out this chick, isn't she hot? *Links to a pic of someone who could easily be a model*
Some Dude 2:Ew, her thighs are like, way too wide. She's kind of ugly.
Some Dude: Yeah, I see what you mean, bro. Elbows too pointy as well. 1/10, would not bone.