This is an effect called posterization, but I had to moderate it a bit so it wasn't quite so overwhelming, since straight posterization is pretty full on as far as effects go. The trick is to balance that one hand while still maintaining a noticeable effect, which in this case is somewhat dependent on viewing distance. So if you're reading this, congrats on clicking through so you can see the full effect.
EXIF data:
3.2 seconds, f/8, ISO 100
40mm focal length
3.2 seconds, f/8, ISO 100
40mm focal length