I'll be honest, I don't really like it. Aside from the in-jokes, it's... too busy. To get these, you'll need screen shots (for the caption game) in addition to the characters interacting with the forum and each other. We need a one-off, not an arc!
I think the answer is to stick to a main joke, and keep it simple. I submit, for your considerations, the following changes;
Keep panel 1 and 2 as is (well, a little editing is probably in order. Later.)
Scrap the caption contest thing in 3. Instead, have Marten looking over Dora's shoulder, saying "Hey, I've seen that one. It's that slice-of-life comic about a guy and his anthro PC".
Dora: "Yeah, but the forums - they're a real piece of work! These people take it WAYYY too seriously!"
Across the counter, Mari (or both Mari and Marten, or all three) recognizes Hanners, who disappeared after panel 1. The line "How can she already have over 1,000 posts? She just registered!" works well with the joke reveal in the 4th panel of the frazzled Hanners.
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Some minor edits; make the title "Controversial Ingredients" (better match with "Content")
Cut "off-planet" in panel 2, and spell it "Marven".