Please don't take offense to anything said below. I am not implying that "unattractive" dancers can't get jobs, or that they have to "make up for it" by dancing better. I personally believe that there is something beautiful in everyone. One of my favorite fashion bloggers, Elaine at Clothed Much, said something similar in her own post about body image.Unfortunately, the rest of the dance world doesn't necessarily see it that way.
Almost everyone wants to change something about themselves. Even if it's not an active thought, even if you think you're good enough as you are, of course you're not perfect. Something could be different, better, more attractive.
In the dance world, these feelings are only heightened. How often are you typecast by skin color, height, body type, or even your face? Especially in the commercial world, there is pressure on dancers to be the model of what society considers to be "perfect" and "hot." The professional ballet world isn't far behind, many times casting dancers for how closely they resemble the dancer that they are replacing so that they'll look "the type" and fit into the same costumes. Obviously, dancers are always judged by their bodies.
There are new movements in dance though. So many different fields, companies, pieces are opening and being created that almost every dancer can find his or her niche. There's a place for every face, every body, every race, every height. Some of the best dancers I know have some of these aspects going "against them," in a conventional sense, but the beauty of their technique and ability is undeniable. Dancers are finally being appreciated for just that: their dancing.
So if you look in the mirror every morning (or during class) with something negative on your mind, remember that there are two more positive things that you could say as well. Don't worry about how you look so much - if someone doesn't like it, maybe you won't book that gig. But if that someone is judging you purely on your looks, do you really want that job? To truly be happy with your dancing and your job, you will find someone or some place that loves you entirely, not just for your "prettiness."