On page 265 I was playing around with the [boxLayer setContentsGravity:kCAGravityResizeAspect]; line to see what the different values would do in the program. When I started changing these values I did not get the results I expected. For example, kCAGravityBottomLeft placed the image in the top left section of the red box. Likewise kCAGravityTopRight placed it in the bottom right section. Why is the top/bottom location inverted?