Hidden Design in Toblerone Logo
The bear hidden in the Toblerone logo.

The principles of optical illusion that are used in these designs, he argues, are based on the psychology of vision and Gestalt theory, which explores the brain’s ability to create whole forms from lines, shapes and curves.

Sometimes the hidden element blends so well into a logo design that they can only be seen if pointed out, such as the bear hidden in the Toblerone logo.