This is only my opinion, but I say it depends on the person in question. I'm one ugly guy, I have no delusions about that, but it doesn't play into my self esteem at all. I have low self esteem (I think, I don't have the psychological knowledge to understand the topic fully) because I am terrible at everything, have no talents or skills, and have yet to accomplish anything nor improve myself meaningfully. My looks are at most a cherry on top of this bitter sundae, and I don't really care for cherries.