Awhile back, fairly shortly after I'd started modeling, I was chatting with a friend about my work with photographers. She commented something to the effect of, "The goal is to make you look good." I fish-mouthed for a moment before gathering my thoughts enough to tell her that it wasn't about making me look good, but about creating something visually interesting. It might entail me looking pretty, it might not.
I've found there to be little room for egos in the world of art modeling. In fact, I try pretty hard to keep mine out of it. It's all too easy to get caught up in how any given image makes me look, but that's not what matters. What matters is how well the image stands, how well it draws in the viewer. And it doesn't have to make me look pretty to do that.