Fixed version of >>736809.
I did it manually, using ffmpeg
to pull exactly the same frame from the episode as in the original (only I used a 1080p copy of the episode) and ImageMagick to crop it down to a perfect(!) square and add the caption. Because of this, the text looks a bit different and the placing is different (better than roflbot’s, IMO), and there’s no watermark! Yay~!