I took a screen shot (command+shift+3 on a Mac and the Print Screen key on a PC) and then edited it down to just the design. Next, I opened a blank document and copy-pasted the left side to the right and the right side to the left. It looked like this:
Tip: You can see the change in position by following shift of the black highlight box. I zoomed in as close as possible and then took another screen shot. Finally, I took the top half and moved it to the bottom using the same procedure as before to produce my tile. I finished it off by changing the center stitches to black.
Now that I have a repeatable tile I can arrange it against itself as many times as I like to make a design.
This process could be used to create some super interesting crochet colorwork, don't you think? Here's another design process using an asymmetrical picture to start.
I am having WAY too much fun with this... Be sure to try it out!