but the voices in my head go

In the Korean comments

One comment points viewers toward Sohee’s changing expressions: in translation, “Our Sohee is an expression vending machine. He really makes them pop. He’s always so varied.” The “vending machine” metaphor praises how readily he produces different expressions.

What the words mean

“쿵짝이 잘 맞다” (kungjjak-i jal matda) literally describes matching rhythmic beats. Here, it is a casual, playful way to say the pair are perfectly in sync or have great chemistry.