It took me awhile to learn that when someone hiding behind a veil on anonymity argues on the internet in bad faith, you cannot win. You can post the most brilliant refuting of their position or have the cleverest barbs against them and/or win everyone else to your side; regardless, you still lose. They are participating in bad faith. You lose as soon as you try to play the game because that is exactly what they want.
Maybe you don't care where that poster posts. Maybe the gif is just a joke to post. But if anyone would rejoice if any other poster stopped posting, just hover over that person's username and click the button to make them go away. Even if its me. My forum using experience got so much better when I exsiced 5-6 posters from my view.