Movie sets are crazier than you think. There are things dropping everywhere, things being reorganized, faces being powdered, frustrations brewing, and all of this on a clock tighter than a blitz time-control.
Once a great shot is captured, that's it. If a chess piece on the board was out of place then it will have to be, or else the budget just might go out the window, and no investor wants that. Besides, a movie is usually still great regardless of a few misplaced items.
Why Movies Get Chess Wrong (article)
Chess is one of the most popular games on Earth. So why do multi-million-dollar blockbusters keep making beginner’s errors?