A little hint here and a little hint there . . . By god that's good. That's very good. In 2001, the scenery, the setting, is as much one of the 'actors' as the humans are. 2001's spaceships, corridors and control panels perform a similar function, swallowing up humanity into their disinfected, air-conditioned machinery, so that the people emerge as disinfected machines.
Humanity is a victim of such environments.
But these environments are man-made. The puzzle loops in on itself. . . . People shape the world around them, and are then shaped in turn by the worlds they have created. Kubrick charts the manmade landscapes of human experience truthfully. On his canvas, the people are indivisible from the background.