Back in 2004, a thread was started by ShrikeArghast. Titled "Can the judges DJP", it led to some confusion within the thread, because a comma would be necessary to turn the title into a command, instead of a question like it was perceived. A quick response came in that thread in the form of "I don't know. Can they?". This thread eventually died off, but a new thread with the same title was made by JesustheDarkLord, poking fun at the original thread. In this new thread, Red Omen answered with "Yes... yes they can. And you can too!" and posted an image of djp himself, with his head bobbing slightly up and down at an angle.

It was then that the term "DJP" was transformed into the motion of bobbing one's head forward/right/left at a downward angle, and many edits ranging from images of djp himself to the Transformers, were edited to make them "DJP".

As an example, here's one that The Coop did, with this explaination of how he made it...

"Copy the girl's head into its own layer. Paste it right on top of the original head. Clean up the copy's edges to get rid of any grass or outfit colors, and then make a copy of that cleaned up head. Turn off the two layers with the copied heads. Use the stamp tool (with "Use all layers" checked) to copy the visually degraded grass and get rid of some of the left side of the girls original head so it won't look odd when you animate the gif. In frame two of the gif, turn on one of the heads and move the head down and to the right a couple clicks, and touch up anything around her neck so it doesn't look so odd. Keep the other copy of the head in its original placement in frame one (make sure it's turned off in frame two though), and export the optimized gif with a timing of .5 on the frames."

-- DJ Tempora and The Coop