Mirrors have many supernatural associations. Vampires, for instance, cast no reflection within them. They invoke spirits if the spirt's name is spoken three times. Sometimes, they can trap spirits or demons (must be a dozen modern movies that still utilize this trope, though the writers don't necessarily even recognize where the trope originates).
It's some very ancient meme (in the true sense of the word) that follows humans around without them even recognizing that it's there.
The thing with vampires was because silver is considered pure (c.f. silver bullet) and ‘could not countenance evil’. iirc this was added quite late in the development of the vampire mythos.
Photography as well. Some cultures thought that having your photograph taken would steal your soul.
My first introduction to this idea as a kid was a great episode of the TMNT cartoon named "Camera Bugged"[0], which had aliens with a camera that actually made people disappear.
[0] https://turtlepedia.fandom.com/wiki/Camera_Bugged