The Mosaic Technique combines rectangles of various sizes. Areas of emphasized focus are treated with a corresponding amount of detail. The effect resembles that of SF art, perhaps suggesting an artificial intelligence at work.
Optical Art is a mathematically-oriented form of (usually) Abstract art, which uses repetition of simple forms and colors to create vibrating effects, moire patterns, an exaggerated sense of depth, foreground-background confusion, and other visual effects.
In a sense all painting is based on tricks of visual perception: using rules of perspective to give the illusion of three-dimensional space, mixing colors to give the impression of light and shadow, and so on. With Optical Art, the rules that the eye applies to makes sense of a visual image are themselves the “subject” of the artwork.