One night, a woman brushing his teeth before going to bed. Look in the mirror, she then realized
there were stains on the surface. She looked closer, and it turns out there are some fingerprints.
She took a towel and rubbed it. But no matter how she tried to clean it, the fingerprint is not lost.
When she noticed more clearly, she later realized that the fingerprint was derived from the other side
of the mirror glass.
