Heinzgate

The emote jphGate is meant to look like some artwork of Makise Kurisu from Steins;Gate where she's talking into a microphone. This is because this piece of artwork is from a scene in Steins;Gate where Makise gives a very long speech about time travel. When Joe was on this scene in his playthrough, on JADS people started posting this picture accompanied with what you're supposed to imagine Makise is saying in her speech. This inspired the creation of jphGate. And the emote's origins still affect how it's used on JADS, because now it's tradition to add a jphGate reaction to long messages. This phenomenon is similar to snailing.

And the reason that Makise is holding a ketchup bottle instead of a microphone in the emote is because of a part in Steins;Gate where someone eats an omelette with ketchup on it, which Joe found strange and argued with chat about. People in JADS refer to the emote as "heinzgate" (a portmanteau of the popular ketchup brand Heinz, and Steins;Gate), because after the emote was made but before it was added to Joe's Twitch channel, it was added to JADS and given the name "heinzgate".