For this puzzle, it is not necessary to identify the paintings, but rather the artists who made them. Obviously, recognizing the paintings will make this step easier, but especially with the Picasso and O’Keeffe, the style may be enough. Filling in the artists and copying the numbered letters below gives the following:
This yields the clue phrase “ACCORDING TO WARHOL, HOW MUCH FAME DOES EACH PERSON GET?” This is a reference to the quote, “In the future everyone will be world-famous for fifteen minutes,” attributed to Andy Warhol. The answer is FIFTEEN MINUTES.