中文说明：可以将两幅图片合成一幅，使观察者在不同距离下看到不同的图片。在较远处看到一幅图片，在较近处看到另一幅图片。
English Description：
Two pictures can be combined into one, so that the observer can see different pictures at different distances. See one picture at a distance and another picture at a distance.