Bridget Riley is a British artist. Around 1960 she began to develop her signature Op Art style consisting of black and white geometric patterns that explore the dynamism of sight and produce a disorienting effect on the eye.
Trees, nature's condos for the little guys, are not just a pretty picture. Squirrels, birds, and bugs count on them for a place to live. (I know the lens is about trees and not art. But I love that face-in-the-trees illusion artwork.