Pareidolia is often used to explain why we sometimes perceive faces in rocks. It is postulated that humans try to make sense of random patterns and in doing so, the brain forms recognisable shapes.
It is our brain attempting to read visual cues. As our visual system attempts to make order from disorder. It can come as a shock when such images are recognised.
Archeologists have found many images recorded on cave walls. The oldest example discovered so far is a red hand stencil in Maltravieso cave, Cáceres, Spain dated using the uranium-thorium method to older than 64,000 years.
It is hard to imagine similar images were not recorded on smaller canvases during the last 64,000 years.
Images recorded on cave walls are rare, images found on smaller rocks are not.