This painting shows the ambiguity of levels, levels of a highway where many cars pass.

If the observation is directed at the outside of the rectangle, then the square road appears flat. However, the road in the middle consists of three levels, even though all the levels are connected to the flat square road.

The world is just an illusion. This is mentioned in the Koran, Ali Imran’s letter, verse 185, “Whereas the life of this world is nothing more than the delusion of enjoyment.”