My idea is bassically to place some stickers in the public toilets mirrors.
These vinyl stickers are black bars or masks to cover the eyes and avoid identification of the person who is watching her or himself. Other idea is the a blurry film that follows the same purpose. This stuff would be next to a explanation legend and logo.
In some of the last pictures I placed in the mirror some silhouettes to help the person to interact, i dont know if it's good idea.