Reminds me of https://www.nature.com/articles/news020926-8 "The 500-year-old Ryoanji Temple garden in Kyoto contains five outcroppings of rocks and moss on a rectangle of raked gravel. Using symmetry calculations the researchers have discovered that the objects imply an image of a tree in the empty space between them that we detect, without being aware of doing so1."

Full article: https://www.nature.com/articles/419359a

Brought to you by the part of my brain which remembers irrelevant nature articles some 20 years later.