Pop art brought art back to the material realization of everyday life, to popular culture in which ordinary people derived most of their visual language in what perceived to be the real world of shopping, movie stars, and car advertisements.
This was thought of as an art that gave off a natural appeal to American artists, living in the midst of an industrial and commercial environment.
In past art styles, women's bodies were often positioned in a way that was pleasing to the male viewer.
Art experts believe the painting is so well-known that it is unsaleable.
In May 1994, Norwegian and British police mounted an undercover sting which uncovered the painting, unharmed, in the seaside town outside Oslo where Edvard Munch painted many of his most famous paintings.
Art theft is now believed to be the most profitable form of criminal activity after drugs and arms trafficking.