The Rubin vase is a famous optical illusion that can be perceived as either a vase or two human profiles facing each other. This duality is a classic example of a figure-ground relationship, where the viewer's perception shifts between the foreground and background. Created by the Danish psychologist Edgar Rubin in 1915, the vase illustrates how our brains interpret visual information. Depending on how one looks at the image, it can evoke different interpretations, showcasing the complexity of human perception and the way we process shapes and forms.