To me it’s the fact that he kept it going for 2 freaking hours… that’s beyond petty A star
Because he's taunting Soohyun to get a reaction from him. In his plan, when Soohyun gets mad or irritated, he probably gonna complain to other about how children lead behaving badly in shooting location.
If it's a senior actor/actress, he probably get told off after a few NG.
2 hours of ng…you’d have to be a saint to not get the least bit upset