Sometimes, I like knowing what my favourite bands look like, 'tis fun knowing.. I don't know why.
Not that it matter what you look like, it's just fun to see because someone could have a gallery of macabre and look like the happiest girl or boy in the world, or the other way around.. *shrugs*
Does it matter what an artist look like? All that really matter is what his or her art is like. Plus it adds a sense of mystery if you dont know the artist, and let you imagine what the artist would look like.