Although I do not go along with ALL of the image comparisons on the video, at 8.22 there's a fascinating example of how a cloning tool is used. That shows how the '1960 Graduation image' may have been created. FOR EXAMPLE:
If you look through a Tyee (U of W yearbook) from the early 1960’s, there are tons and tons of photos of girls wearing dark sweaters with that neckline and a string of pearls. They had an almost infinite resource available for photo parts.