Where: Cologne, Germany
The foreground is a silhouette of a chair back. The chair is in front of a wall with small holes allowing one to see through to the other side.
What I found intriguing was the shadow being cast on the wall from another table with a flower. If you look long enough, the image becomes more interesting and quite confusing as the brain tries to determine if the shadow of the flower is coming from behind camera, or coming from the other side of the wall.