Turns out that when James Cameron wanted to use the Picasso image in the movie the Artists Rights Society and VAGA who look out for Picasso copyright amongst others said no. This group is also the reason that no works by Picassos are included in the Google Art Project. But could they stop Cameron? Not a chance, although he did have to fess up with the fee when pushed later. Now he's being hit up again for the 3D version. Good luck with that.
