@noelle Yeah, that's been other people's answer since I posted this, but now that just makes it odd because people carried the trope into the modern day, where mirrors generally aren't made using silver anymore.
@noelle@Jo they might not even know they're doing it
they're just wandering around, seemingly obviously visible, and are too busy nomming on villagers to concern themselves with why these newfangled mirror thingies don't work for them