
Hans Holbein the Younger, a German painter famous for portraits so detailed they look almost like photographs.
Two well-dressed men stand on either side of a shelf full of books, globes, and musical instruments.
Painted in 1533, it shows two friends, an ambassador and a bishop, surrounded by objects that show how smart and worldly they were.
Holbein painted every fabric, book, and tool with such care that you can almost feel the velvet and the shiny brass.
A strange gray shape floats near the floor, but if you look from the side it turns into a skull, a clever hidden trick.
You can visit this painting at the National Gallery in London.
The hidden skull only looks right when you stand at the edge and peek across the picture, like a secret puzzle.