What you are describing sounds like a "collage".
However, there is an extreme variation on that theme which uses many, many more images and categorizes them according to the average color of each image. Then, using those individual images as individual pixels of the final image, an image is reconstructed using literally thousands of tiny images, each of which only contributes its average color towards the making of a recognizable overall image, with the tiny images just barely recognizable as individtual images.
I think the software to do the latter comes with HP cameras as part of the bundled software.
I thought that the former, collage, was a capability of PSCS, but I don't see it anywhere in the Help file, nor do I see such a capability in Micrografx Picture Publisher or Irfanview.