The show stops mid-joke to complain about how short it is, then complains about the complaints. Gintama fans already know this is where the real comedy lives, not in the plot, but in how aggressively it refuses to take itself seriously for even thirty seconds. By the time you realize you've watched eleven minutes of trailer wrapped in callbacks, you're laughing at the same thing the show is laughing at.
This Gintama special came bundled with the limited edition DVD of Gintama: Shinyaku Benizakura-hen. It plays on a recurring Gintama gag in which the animators recycle the same New Year footage. The Yorozuya crew sit around the kotatsu with a bowl of tangerines and talk over elaborate topics. Shinpachi grumbles about the reused animation, and Gintoki wraps things up with a pointless announcement.