Host Deane Hutton from Australia's vintage children's program The Curiosity Show demonstrates the optical illusion called an Ames window.
The trapezoid is named after American ophthalmologist Adelbert Ames Jr., who first demonstrated the phenomenon. Ames is probably better known for the Ames room:
Ames rooms have been used in a number of music videos and films, perhaps most notably in Eternal Sunshine of the Spotless Mind:
Image: youTibe / CuriosityShow