Miss Manners has some excellent comments on the information conveyed by one’s choice of clothing:
…clothing is a social language that everyone reads, consciously or not. Any job counselor, costume designer or defense lawyer will attest to that.
Is this shallow? Well, it is undoubtedly on the surface. But sometimes that is all one can see, and even those with the opportunity to dig deeper still have to deal with the surface.
Unlike beauty or other physical characteristics, dress is presumed to be subject to some degree of choice. You may choose to be as close or as remote from the prevailing convention of the time and occasion as you like, but the distance will be read as reflecting your attitude. This is why movie stars and hip-hop musicians dress so differently when they go to court. Such symbolism is powerful, and those who use it to lie should not be surprised or offended when others take these statements at face value and presume them to be childish or criminal.
Too many people are happy to latch onto the cliche of “Don’t judge a book by its cover” when convenient for them. In fact, the cover of a book often says a great deal about what’s inside. Just as with clothing, it was designed to do just that.