not this song but #Hearts2Hearts

In the Korean comments

One comment points out, in translation, “The background is looping,” giving viewers a specific edit to watch for. Another describes the members’ contrasting reactions: Jueun ignores the absorbed 다정즈 (Dajeongz, a nickname for the pair), while their leader cannot handle the duo’s energy.

What the words mean

고능하다 (goneunghada) literally suggests “high ability,” but here it is casual fandom slang praising Jueun as remarkably capable or sharp in the background.