@birbiebi She says in this clip that it's a reference to mono in music, which means one unified sound, not split into left and right. So whether you hear it from the left speaker or the right speaker, it's the same sound.
I’m going to be pretty busy for a while but I’ll be working on a Dancae doujinshi on the side…! It’s going to be modern au with hong kong 80s/90s vibes. (It will most likely be finished next year ㅇ(-< )