'Star Trace' Release Countdown Day 12

In the Korean comments

The joke is the tiny squeaking sound assigned to Eunho. One top comment reads, in translation, “Is that little-cute sound officially Eunho’s sound effect?” Another calls it “Eunho’s personal squeak-squeak effect,” while another laughs that a sound already associated with him is now being used by the official account.

What the words mean

뽀짝 (ppojjak, tiny and adorably cute) is not simply a transcription of the noise. In phrases such as 뽀짝소리 (ppojjak-sori, little-cute sound), commenters use it affectionately to make Eunho’s squeaking effect—and by extension his movements—sound especially small and cute. The register is playful fan slang.