Who is Andy Warhol?

From the review What is an Andy Warhol in the NY Review of Books.

...Warhol realized that you don't need to make art for an audience brought up on film and television in the way Kenneth Clark defined art. [Marilyn Monroe] and [Warhol] grasped that in the modern world, presentation counts for more than substance. The less you do, the greater may be the impact....

A silk-screened image is flat, and without depth or volume. This perfectly suited Warhol because in painting Marilyn Monroe he wasn't painting a woman of flesh, blood, and psychological complexity but a publicity photograph of a commodity created in a Hollywood studio. As Colin Clark's anecdote suggests, you can't look at Warhol's Marilyn in the same way that you look at a painting by Rembrandt or Titian because Warhol isn't interested in any of the things those artists were—the representation of material reality, the exploration of character, or the creation of pictorial illusion.

Warhol asked different questions about art. How does it differ from any other commodity? What value do we place on originality, invention, rarity, and the uniqueness of the art object? To do this he revisited long-neglected artistic genres such as history painting in his disaster series, still life in his soup cans and Brillo boxes, and the society portrait in Ethel Scull Thirty-Six Times. Though Warhol isn't always seen as a conceptual artist, his most perceptive critic, Arthur C. Danto, calls him "the nearest thing to a philosophical genius the history of art has produced."

[In the Red Self Portraits (1965)] Warhol presents himself as insolent and impassive, in the take-it-or-leave-it stance of the hustler or gangster. Out of register, like a color TV on the blink, the person in the portrait is a new kind of human being, one trapped in some fathomless, unreal televisual space, without physical mass or emotional depth. The dead, unseeing eyes in the self-portrait suggest that he was perfectly serious when he said, "If you want to know all about Andy Warhol, just look at the surface: of my paintings and films and me, and there I am. There's nothing behind it."