
Simply watch the image being drawn, using fewer and fewer colors. Zoom in to see that pretty accurate dithering requires very few colors! 7 images will be drawn, the last one being the same as the thumbnail. If it looks weird, zoom in on the hair/beard of @NPRGuy, or the ocean waves. You'll see that they use very few colors and "mix" them to make it look like another color!
This has apparently been done before but honestly I like mine better. I could add some extra features... https://en.wikipedia.org/wiki/Floyd%E2%80%93Steinberg_dithering The thumbnail is using only 1-bit values for red, green, and blue, meaning it only uses the colors black, blue, green, cyan, red, magenta, yellow, and white. Even so, it looks really good!