Christmas crafts: How to make your own amazing optical illusion
How it works
In one sense, getting this to work could hardly be simpler. Just prop (or stick) the right-hand page of the centrefold against a wall so it is at 90 degrees to the left-hand page, which should be on a flat, horizontal surface. Then step away and adjust your standing position until the distorted image appears perfectly in 3D (see above).
Yet, in another sense, how this works is actually pretty complicated. Like any visual illusion, anamorphic illusions such as this one trick your brain by taking advantage of the way that we stitch together reality from …