Pop art is art that is based on evryday things and famous people, such as soup cans or Mickey Mouse. A famous example is Andy Warhol, who is famous for alternate colors with common objects or famous people.

My examples! I adjusted the threshold of my portrait, added some shapes, and adjusted the colors for each one.
kendrick_popart.jpg
And the four that it is made from: I split them by selecting half of one with the Rectangular selection tool, moving parts around and having the different colors on different layers.
popartred.jpg
popartyellow.jpg
popartgreen.jpg
popartblue.jpg