It has been suggested that as humans, we are attracted visually to essentially three things. One is the illusion of depth. Receding lines. Foreground/background. Second, we like eyes. Or, when the subject has what appears to be eyes like a pair of circular shapes. The third attraction is a mystery. We are drawn to what we initially can't understand. It's a puzzle. Often in my work, I present such a phenomenon. But I like to include a clue. In the first case below, all there is to go on is a rocky outcropping. but at this coastal spot, the mossy growth was the most dazzling green I have ever seen. It was almost a light source in itself. It was an optical illusion too-- it appeared as green smoke!