I Know! I wonder what the different things mean
I have a hunch that it means the personalities of the people? Im not too sure
maybe, his mom seems like a really bad personality and had shattered glass so maybe it means something about her sharp mind and way of acting, was broken. Also he said before that he knew MC was telling a lie about having a boy friend when the pink haired girl told him. Maybe he can see when people lie or something. I know he dose not see it on the MC but by looking at other people he could have came to that conclusion, or she was being see through when telling the lie lol. I will just have to wait and see lol!
Actually his dad the one who have glass while his mom have steel
So segye has a power too, omg that's so shocking if ye-chan can see the other people thoughts segye can see something around the other peoples neck like flowers or thorns Σ(っ°Д °;)っ