Place this clip just after the pointless task is revealed in your edit, then follow it with an emotional damage sound for the robot's reaction moment, keeping the original scene audio underneath so the exchange stays clear and connected.
关于此声音
This is Rick Sanchez giving his small butter-passing robot its only instruction, 'you pass butter,' in a flat, matter-of-fact voice over about seven seconds. The delivery feels bleakly funny and a little existential, as the robot realises its whole purpose is that one trivial task. It comes from Rick and Morty season 1 episode 9, 'Something Ricked This Way Comes.'