Tastefully Yours

Basically this is the scene where Ji-hoon's character meets the actor of Choi Hyo-man's character. You're Ji-hoon (his character) and basically Choi Hyo-man's character asked "if you don't mind me asking, which high school did you go to?" then your smile fades and your eye gaze changes (becomes si-eun's dull, emotionless eyes) and he's intimidated because he remembers you from his high school and you were very intimidating in his perspective.