Appearance is very important and also represents what is inside, in the soul. Someone who is ugly isn't like this for no reason. As one example, a severe blockage in the throat-chakra can cause one to develop an "ugly" head and face. These things can slowly be fixed over time by unblocking the chakra fully and cleaning it.
Everything from how someone's face is shaped, their eyes, nose, lips, forehead, hair, to how someone's wrists and palms, fingers, look like, all can give extremely detailed insights on the person.
Beauty is also to a degree in the eye of the beholder. Many people have bad past-life karma where they were abused by a specific person, and others who have similar appearance-traits now in this life may seem scary or ugly to that person. Same goes for the other end of the spectrum. Past-life attractions can make specific facial-shapes seem far more attractive to you than they are for someone else.
The issue with "beauty" nowadays is that it is skewed by the Yehuborim media. Not everyone who has a properly shaped face and a body that is in shape and clean, would also automatically be a nice person.
I remember seeing the picture of a woman who as regarded as "beautiful" and "sexy", who in reality had huge tendencies to play around and deceive men, shallow and disloyal. Most men wouldn't actually want that as a partner.