001905 ‘Retrieve arms’ is a recurring gag from earlier MSPAs that fans liked to call back to. I can’t really emphasize this enough that at this stage of the game, Hussie was very much in a literal dialogue with his fans where each page was a response to their input. Callbacks and retread jokes come up again and again as much because the readers brought them up as Hussie did.
The panel of course refers to him as ‘pooplord’ too, just to call back to the even more recent joke.
We also get a pretty good look at another one of John’s posters here. One for Problem Sleuth, the MSPA immediately preceding Homestuck- an adventure Homestuck would end up mirroring in terms of structure more than i would have guessed initially.