The riddle is an Infinity Mirror and motion sensor. When players approach the mirror they heard a terrible sound, and a witch appears in the mirror. Behind the mirror, you can hide a hint or In the mirror, a secret niche may open. Item or hint can be used in another puzzle in room escape.
* You can change the way the puzzle is activated. For example, you need to shout at the mirror. But you can do so on the picture frame, players need to install the missing parts for activation.