@silverdust totally agree. I understand why people dislike her but the main reason she's being mean to MODEL-Yeseul is because she was picked as a model over her. It's pure jealousy that's taking form because the make up guy (can't think of his name) turned her down for Yeseul. Without make up guy there's no jealousy / no reason to be mean to her. She dislikes the fact that she was overlooked for someone else so she's assuming she lost out to someone who has a form of physical beauty superior to her own. She said in her own thoughts that her looks are the only true power she has and that's a huge form of insecurity. It's obvious she has major hangups about only being "eye candy" and she projects that all over the place at the rate of a fire hose.
She said, "No matter what I see under that costume I won't like it", but it wasn't about looks per say it was more about the fact that the jealousy hurts her so much coupled with the fact that she can't get the satisfaction of seeing
why someone else would be picked over her. She feels like Yeseul is rubbing it in, which she's not, but even in that case it's still anger spawned from make up guy picking someone else over her -- someone that won't even grant her the satisfaction of showing her why she wasn't picked and it's driving her mad in the total opposite way that Yeseul's kindness drives her mad in a positive way. She's a tale of two extremes. Two sides of the same coin.
I realize why people would dislike her but I really do enjoy the fact that she's not only believable but seems like a whole character. This author is top notch.