Sergio Muñoz Sarmiento points to a strange case in the Court of Federal Claims which ruled that a postage stamp featuring a photograph of a sculpture was a fair use. The Court held that the stamp was "transformative, providing a different expressive character than [the sculpture]." The photograph "transformed [the sculpture's] expression and message, creating a surrealistic environment with snow and subdued lighting." It all "resulted in a work that has a new and different character than [the sculpture]." Not a particularly tough standard to meet.
Sergio wonders whether "sculpture has been gutted of copyright protection." I don't know about that, but it's another good example of how you can make the traditional four-factor fair use analysis do whatever you want it to do. As Judge Kozinski has said, the analysis can always go in either direction. The result is just massive uncertainty for all concerned.