Informal Awareness in a Hallway

Just saw a very insightful "hidden" camera view of a workplace hallway taken by Saul Greenberg back in the early 90s (at least that's what the presenter said). Essentially, a hidden camera was placed at an end of a office hallway allowing the viewer to see how people casually peered into offices as they walked by to create an informal awareness of the people in their immediate surroundings.