Mrs. Höss describes to her friends getting a coat from "Canada" while mocking another woman who thought she meant the sovereign country; Kanada was in fact the name given in Auschwitz to the vast storehouse of goods confiscated from the prisoners.
Alexandria, the young Polish girl leaving apples for the starving prisoners, was 90 years old when she met Glazer and died shortly after. The bike the film uses and the dress the actress wears both belonged to her.
The sound of constant revving of an unseen motorcycle engine heard from a distance several times throughout the outdoor scenes is a fact from real life. The main character of the movie, Auschwitz commander Rudolf Höss, hired a person just to rev the engine in order to overshadow the horror of screams and gunshots coming from the camp.
Director Jonathan Glazer used up to five fixed cameras in the house and garden with no visible crew to capture many scenes so the actors didn't know if they were being shot in a close-up or wide shot. They were totally immersed in the scene and enjoyed working in that realistic environment.
Due to the unconventional multi-camera set up, Glazer and his team had over 800 hours of raw footage at the start of the editing process.