The thing you have to remember is that a movie or TV show is a completed invented work. Nothing in it just happened. A bear didn’t walk on to the set and start eating birdseed while the camera just happened to be recording.
Somebody picked the location. Somebody put a bird feeder in that spot and filled it with seed. Somebody went out and rented a bear and hired its trainer. Somebody set up the camera and lights and microphones.
There’s nothing spontaneous in a movie or television series. Everything is there for a reason and is part of the story.