David A. Goldfarb said:
How many years after Rejlander?
I would put Rejlander into a different category than Hockney, as Rejlander used multi-printing techniques and copying (like H.P Robinson, Uelsmann, etc.) to create tableaus. For that matter why pick Rejlander when Henry Peach Robinson could also be used as an example?
However, neither Robinson nor Rejlander did the same thing as Hockney. Rejlander and Robinson wanted to fool you into thinking the image was a made from a single exposure. They "built" images that emulated the look of a single exposure but could not be made unless they were constructed from multiple images. However, they went to great lengths to HIDE the fact that the image was made from separate, individual exposures.
Hockney purposely shows you that you can't make the image without hundreds of single exposures put together to make the final image. He's purposely exploiting and showing the look and distortions of multiple exposures that mean nothing until assembled into the final image.
He's purposely showing the assembled whole as a means to deconstruct the idea of the single exposure = single image (among many ideas contained in his images).
Does that clarify the difference for you?