The gray square to the left of the red square in question has both of its seams ironed "out" and the red square has both of its seams ironed "in." That is why on the back the gray one looks bigger than the red one but they are both the same cut and sewn size. If you started with 5" squares, the gray one is shown at 5" wide and the red one at 4 1/2" wide. The others are shown at 4 3/4" wide (one seam out and one in as the seams were all sewn to one side). Hope that makes sense.