? In fact, the cut out of the chocolate block on the surface seems to be able to each other "seamless" together, but, just because of the slope of the same slope cut, the final rectangle than the initial rectangle to shorten a small cut, and the missing "small cut" area is exactly the area of an extra block, it is not possible to increase the chocolate out of thin air, it is all just a visual misalignment. "The area of the missing rectangles happens to be the area of the extra block, and the chocolate can't be added out of thin air, it's all just a visual dislocation.