GIFs are definitely something that Reddit readers upvote. The ones that are most liked are the ones that show something quirky and spontaneous. So instead of always posting the grand image of a battle and so forth, post a silly-stupid moment that any gamer can identify with. Or, even better, anyone can identify with.
Surely @SpaceJay has experienced times when he was trying to shoot a scene and somebody crashed into him. Or unintentionally flew right into his field of view Or something like that. It shows a bit of the human condition. That’s very popular on Reddit. The fact that it’s in Battlescape should be incidental. Then people see the GIF and say “That’s hilarious/awesome/typical. What’s that from?” Then they feel like they discovered the game instead of feeling like yet another marketing effort shoved yet another game in their face.
In other words, stop being so serious about getting the word out. Have some fun with it. This is game right? This is supposed to be fun.