CMYK stands for cyan, magenta, yellow, and key (black) and it is the color model used for color printing. In theory,when cyan, magenta, and yellow are mixed together evenly, they should create black. But the truth is that is practice, they do not; so black is added into the model.
The piece above falls into the genre "Pop Art". Pop Art is art based on modern popular culture (pop culture). It is widely used in mass media. It is different from traditional art in that "material is sometimes visually removed from its known context, isolated, and/or combined with unrelated material" (http://en.wikipedia.org/wiki/Pop_art).