I zoomed in as large as my browser would allow. I agree with joe's mom. I think it's an optical illusion due to the striped fabric. If you zoom in and look at the fuchsia block on the right, and the green/tan one above it you can see that it's just striped fabric. The blocks wind up with the bias at the outside edges. Some of the blocks are quite square, with the seams hitting the corners perfectly. Looks like some of them got stretched a bit and the seams got misplaced.