It's classy cause most of those myths start to loosely become related to mirrors.(idk if you've ever seen Constantine but that's basically why he used the mirror on the demon in the beginning)
There's a whole cosmo/theo/mythological thing on it i'm only recently beginning to understand how it interconnects in the DF to other idea's like the shadow, the order of the mind itself, and the mind, body, will triangle.(if so limited)
I wouldn't be surprised if mirrors became very, very important. Harry frequently mentions in the early books that he doesn't own any mirrors, because too many things can look back at you. The fetches came through reflective surfaces, too, which I don't find enough of a payoff for Harry's paranoia early on.
