Abstract
Lady Gaga's fourth CD album ARTPOP, designed by American pop artist Jeff Koons, adopted one of my illusion works, namely, Hatpin urchin, as the main inside design. This occurrence was significant for the study of visual illusion in the following three senses: first, it drew people's attention to visual illusion; second, the chosen illusion was novel; and third, for the first time in its history, visual illusion was recognized as ubiquitous.
