Blurred, as if seen from across the room: a skull.
Two pictures in one
All Is Vanity
A woman sits at her dressing table. What else can you see?
A huge skull: the mirror is its top, her head and its reflection are its eyes, and the bottles on the table are its teeth.
Why? Your brain groups the shapes one way or the other, but not both at once. Charles Allan Gilbert drew it in 1892, when he was 18.
Picture: Charles Allan Gilbert, Public domain · Wikipedia(opens in a new tab)