Just finished rereading seasons 1 and 2 and I'm fairly sure the "video" from the club is used to threaten blondie. Chun is using it as a leverage, I guess, to get back at either Kwon or Yeon-oh. Blondie probably hasn't seen the content and just assumed it shows his involvement.
The camera lens is on the handle of that bucket. I don't know which side, but one is facing the door, the other on the middle part of the sectional where the straight guy (who didn't want to participate) was sitting. They never change position the whole time, which led me to believe that author deliberately made Chun's goon foil their own plan. I bet he shares the same bruises as blondie. I think this is how blondie will pay for his sins—to be used by Chun.
Anyways, if we're lucky, it has audio as well, and that would be all they got plus footage (if the camera is facing the door) of Yeon-oh hitting the table, him grabbing the bottle to whack it on that aggressive guy's head, and the latter responding by saying he'll kill Yeon-oh. It should also show Yeon-oh getting away and being pursued.
So, there.
...but is simply not ready to wear his heart on his sleeve. Now, I realized that maybe he has never fallen in love yet....? He's obviously not aromantic, the way he's been behaving... I do believe that there's something there for Yeon-Oh. Seme is obviously just emotionally stunted due to his mother's untimely demise (if he still keeps and visits her childhood home, then she must have been very important to him and it means something that he welcomed Yeon-Oh there)...the people around him growing up (his corrupt father and his evil grandfather).
If you have the nerve to approach the injured party for help, you can do the same to Kwon Jaehyuk. Atleast, he'll listen to you. ( ̄へ ̄)