I have been further refining my multiscale mosaic technique in search of the overriding goal of reconstructing an image from sub-images in such a way that balances the clarity of the large target image and the sub-images. I have tried out lots of ideas and the ones that seem to have the most potential for creating interesting multiscale mosaics are:
I have used a cropped region of Vincent Van Gogh's painting Self-Portrait With Grey Felt Hat as my target image while developing these ideas. The sub-images are sections of Van Gogh paintings. They are either the central squares or a few are manually selected square regions that focus on some interesting detail.
These techniques do seem capable of producing interesting mosaic images that can carry meaning at multiple visual scales.