Below is a 4 min. and 12 second wonderful montage of scary mirror sequences from numerous films. This would have been a wonderful SHOCKtober post, but we can love it now, can't we?
P.S. At the 1:20 mark you will see an actual dramatization of THE YOUNG FUTURIST! being scared by a bedraggled child creature in a mirror. It's good. Watch for it.