It’s obvious that De Palma loves cinema, and that comes across in the films he makes. But no more so than Body Double. The story develops slowly, and I won’t ruin it here, but it is solid and satisfying.
I look at Errol Morris’s first two films, Vernon, Florida and Gates of Heaven, as learning experiences for the film-maker. Both, on the surface, are not really about a particular topic. But both have themes that show up while you are watching the films. It was if Morris set out to make these films without a grasp of what he wanted to show up on screen. And while filming, he found a theme through his dialog with his subjects.