The phrase comes from Korean, where nun means eyes, semo means triangle and nemo means square, a nonsense image that is easy to picture and repeat. Clips using the phrase circulate mainly as short form meme audio, shared on soundboards for quick playback and download. Its appeal does not depend on understanding a longer scene, because the rhythm and repetition carry the joke on their own. That makes it reusable across reaction edits, fancasts and silly face compilations, where creators need a recognisable cue for stunned confusion.