This step by step reconstruction of the Scotty meets Gavin scene in “Vertigo” by Alfred Hitchcock may seem like the narrator is reading too much into an early part of the movie. But he’s exactly right. Hitchcock would storyboard every element of a movie before actually committing it to film. There was no improvisation on his set.
In fact, Hitchcock used to say that the actual filming of his movies were the least complicated, and sometimes most boring, part of the process, because he had essentially completed the production before filming began.