The first 2 mosaics were made in 2004 using only Photoshop. I teach myself how to these on my own. Which is why the two mosaics look like they were made differently, because they were.
This was before digital cameras were widely used, and to my knowledge before any available automatic mosaics program.
When I made this each photo had to be scan, crop/resized, and correctly position, and merge. Another layer was made for the main photo. The main photo layer and the merge layer were overlap and crop to be the same size. I went back and forth making the merge layer to look like the main photo layer.