This painting presents the ambiguity of the levels of the house.

If you search from the door on the left, then go up to the second level, then the door on the right is on the top level because it is parallel to the second level floor.

However, if you follow the road from the door on the right, then the door on the right is at the same level as the right door, because the road is flat, which is indicated by the same flat pool of water.