Many people at the time were equally shocked she wasn't nominated, particularly since Laughton and Lanchester were. Dietrich did win the Golden Globe for her performance as I recall.
She's in a pissy mood through much of the interview, tries to pick fights with Schell about her films (which she mainly disparages), and generally sounds cranky and uncooperative. Her daughter said she was in ill health through much of her later life, and that might have been behind her sour...