Was just sharing this with my girls and thought I'd share it here just in case there's someone not aware of this. ALWAYS check mirrors in dressing rooms/bathrooms....put your finger on the mirror, and if there's not a space (as shown), that means it's a 2 way mirror (creepy...no?!)
More old wives tale than fact, don't get TOO paranoid, a normal thin mirror will have "no space" go try it yourself on a small mirror.
It would most likely act like this on a Grand (thick) decorative mirror possibly, over anything else, due to the thickness of the "looking glass" rather than it being 2 way.
