Image Credit:
These two images of the Leaning Tower of Pisa are identical but if you look at them closely you'll notice that the tower on the right appears to be leaning more than the one on the left even though there is no difference between the two. This illusion won the Best Visual Illusion of the Year contest in 2007.
Observe very well, the edge are a little different at the bottom for the image, yes both pics they were taken in the same place, but not in the position for the Camara. In one the Camara was straight and the other one the Camara was more vented to the front , I am not expert in these things but I was trying to find the answer. LOL