Here is yet another example of perspective. Both of the black boxes (rectangles) are the exact same size, but it sure appears that the one in the lower right is much smaller. Even knowing that they are the same size, it’s still tough to imagine that they are as your eyes move back and forth between the two! Keep looking through our optical illusions, you’ll find plenty more good pictures of optical illusions!
This is also a good example of one point perspective, where all lines are meeting/converging at a single point on the page. Each other line is horizontally parallel.