Looks aren't everything. Don't judge a book by its cover. Other cliches are apropos to this scenario--good looks don't necessarily mean a good employee. How one carries oneself in everyday situations is more important for workers in any setting. Good manners are part of fostering a good work environment and good employees.
I think that, given a modicum of civility on the part of the one being interviewed, the person who is more put together physically and more attractive on the outside is going to get the job if they have the right skills and education and sometimes if they do not.