The best method is to compare the image in sections. Start at one corner, move slowly across the top, then repeat through the center and bottom. Pay attention to outlines, repeated objects, direction, color, and small gaps rather than staring only at the most obvious subject.
There is no need to rush. The challenge is not a serious measure of intelligence; it is a simple test of attention and patience. Once the changed detail becomes visible, it often seems impossible that it was ever hidden.
Visual challenges become popular because
