Wow, that's a tough one. The only thing I could think of is that the feature is based on the dolly zoom effect that Hitchcock created, where the foreground stays the same, but the background gets smaller or bigger?
Nope, not even close. A clue...SF Gate has the answer.
A portrait was hung in the Legion of Honor for 'Vertigo.' No one's seen it since
By Katie Dowd, SFGATE, September 14, 2019
The painting is lost. It was just a prop at the museum and got lost after they tore down the set. The suspicion is one of the set decorators took it home. Not set decorators have passed on.
The fourth painter, John Ferren, was a founding member of The Club, an American group of abstract expressionist artists. He'd done some work for "The Trouble with Harry," another Hitchcock film. Ferren was in Los Angeles at the time the shoot was getting set up in San Francisco, so he set to work on the revised portrait. The piece, obvious enough for the film but still elegantly rendered, was a winner.
The people trying to find the painting tried contacting Ferren's son Bran who, you may be surprised to learn, holds the patent to the pinch-to-zoom technology utilized by smartphones.
Now you know the rest of the story.