Complex sentence: The bulk of the film consists of mostly unconnected segments: commercials, shorts, and trailers for fictional movies, shown during a Congressional Oversight Committee hearing as a representative day of TunnelVision programming.
Split into simpler sentences: The bulk of the movie consists of commercials, shorts, and trailers for fictional movies that are usually not connected to one another. These are being shown during a Congressional Oversight Committee hearing as a representative day of TunnelVision programming.