The Penrose Rectangle is what’s known as an impossible object, an optical illusion that is drawn to look like a three-dimensional thing that could never actually exist. If it’s hard to see at first, cover one half, then the other, and then look at it again—it’s a geometrically impossible shape.
Impossible forms are a TKSST favorite, as proven by the site’s logo. If you draw any impossible objects, share a photo with @thekidshouldseethis.
There are more optical illusion videos in the archives, including the not-to-be-missed work of Kokichi Sugihara, who builds impossible drawings in three dimensions.