This painting depicts four towers in a row united by a square frame.

The shape of the tower is of course parallel between the bottom and the top. However, the four parallel towers can be connected with a square box where the frontmost and rearmost parts should be in different positions.

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.”