Don’t recall what year it was from, but definitely after 2010. Might have been an additional add-on that was included in the “reel” of short films that circulated to the theatres that wasn’t actually a nominated short film.
I don’t even recall whether it was live action or animation, although I’m leaning towards animation.
What I recall of the plot was that an old man and an old woman are alone in an institutional sort of room that’s in a state of disrepair or otherwise looks somewhat abandoned. And they hate each other. He dies at the end and she’s quite gleeful about it. The action, such as it is, seems to be reciprocal, (maybe they were doing something akin to playing a chess game?) with each of them taking turns doing (something) and the other person glaring and wishing ill as they did so.
I don’t think there were any other characters in the short, just the two of them.
I have the vague notion that either a window or a mirror figured into things, but I’m unsure about that.
I know it’s not much to go on, but does this ring a bell with anyone?