I have two examples of this that feature work in the style of Jackson Pollock. From the point of view of an artistic producer, at art school I was set a project to make a painting that combined two existing images. I chose a Pollock painting and a Futurist cyclist. The library had a book on the Futurists that had the preparatory sketches for the painting of the cyclist, showing how the forms of the finished painting had been abstracted from a fairly literal sketch of a man on a bicycle. This allowed me to understand and reproduce the compositional structure of the piece far more effectively than just copying the finished result would have.
From the point of view of an artistic consumer, Art & Language did some wonderful paintings of and titled “A Portrait of Lenin In The Style Of Jackson Pollock” around 1980. They made sketches of the images before painting them, and these are very useful if you can’t quite “get” the images when you first see them. Those sketches are often reproduced in exhibition catalogues and are available online.
Having access to the source material for even traditional media like painting can be very valuable for both consumers and producers. For consumers, it’s like being able to read the source code to figure out what’s going on in the binary. For producers, it enables remaking, reworking or build on the original work as surely as being able to hack and make the sources to a binary.