Our brains get confused when three-dimensional reality is mixed in with two dimensions. Our binocular vision is dependent on the angles between the eyes and various cues from the objects. If an object can be shaped to match these angles perfectly, then the brain is fooled into thinking that it is seeing a 3-D object instead of a flat illustration. Our brains takes visual cues and construct a false reality, which can be easily manipulated.
Watch these videos to see your brain warp the truth!