He only wanted her for her body--to paint, of course....
I just saw this film and found it absolutely delightful. As others have noted, Helen Mirren is a wonder as a young girl working out the relationship between her body's strength and its beauty, and how each can help her get what she wants. There is one moment, when she takes control of a motorboat after having dumped a would-be lover overboard, when I saw the future Jane Tennison. James Mason is also marvelous as the obsessive painter. The natural setting, on the Great Barrier Reef, is liberating and beautiful but the heart of the movie is the little cabin which goes from a dump to a layered, painted work of art. This man's passion to make things, to create color and line on every available surface, seems to fill the movie's surface too. Near the end, when Cora enters the cabin and we see her surrounded by his paintings of her, the relationship between art and life seems to be a very happy one. It's too bad Michael Powell didn't get to make more films in the 1960s and early 70s. I think that if I could have seen this film at the time it was made (when I was a girl in my late teens, for whom nudity was not an option) it would have meant a lot to me.