B Roll. This is the behind the scenes footage Hollywood studios provide. PR for a film. Usually spliced in when broadcasting a celebrity interview to give "atmosphere".
But I find the mega budget production aspects fascinating. Seeing the million dollar DaVinci Resolve boards. The robotic Oculus camera cranes. As well as the intricate stunt choreography and wire work for Guardians 2. The massive alien ship interior sets for Arrival. The ballroom in Beauty and the Beast.
Another recent good one: Murder on the Orient Express. Istanbul's Sirkeci Rail Station. And a snow bound cliff outside Vincovci. All recreated on London sound stages. And shot in vintage large format Panavision 65mm analog film cameras ;)
Behind The Scenes On Murder on the Orient Express