It may be worthwhile for you to consult with an employment law attorney. If this action is a form of sexual harassment or discrimination, which it might be (e.g. a male boss favoring a more attractive woman could be a form of sexual discrimination), you may have a cause of action. On the other hand, "looks" are not specifically protected--companies *may* discriminate on the basis of attractiveness, or how "presentable" a person is, especially in a position which deals with the public, so long as it is not discrimination on the basis of sex (or race, or age, or disability, or religion--i.e. not discrimation against one of the protected categories).Since whether you have a claim or not depends on the specifics of the situation, it is worthwhile for  you to consult with an employment attorney.