Fly on the wall
Fly-on-the-wall is a style of documentary-making used in film and television production. The name derived from the idea that events are seen candidly, as a fly on a wall might see them. In the purest form of fly-on-the-wall documentary-making, the camera crew works as unobtrusively as possible; however, it is also common for participants to be interviewed, often by an off-camera voice.
Examples include American Factory, Cops, Deadliest Catch, Survivor, Big Brother, Dynamo: Magician Impossible, Educating... and Weiner.
The format has also been spoofed, notably in 2001 BBC comedy The Office, based at a paper merchant in Slough.