(rereading this) I remember that the reasons why vampires couldn't see themselves in a mirror was originally because the mirror coating for mirrors during the period were made of silver. a holy metal. by this technicality, they should still see their reflections in pools of water and bronze mirrors of that period AND should be able to see themselves in modern mirrors. author-san gave us an explanation, but it can be an unreliable information- but hey, they do serve the character dynamic .