Figure 7.1 The Margaret Thatcher Illusion The top and bottom row of images of former Prime Minister Margaret Thatcher are identical to each other but flipped vertically. The top row looks like two upside-down Thatchers, but the bottom row looks like a Thatcher on the left and grotesque mutant Thatcher on the right. You do not notice that the Thatcher at the upper right is the mutant Thatcher because the eyes and mouth are right side up although the overall face is upside down.
(Courtesy of Peter Thompson. From “Margaret Thatcher: A new illusion,” by P. Thompson, 1980, Perception, 9, 383–384.)