2AM's Changmin shades his mouth?

Some of you might not even understand the title but just let Hyuna explain. On today's episode of Star Golden Bell, Hyuna said, "Usually when people put on makeup, they add shading on their cheeks and chins to make their faces seem smaller. But with Changmin, you add it near his mouth." Even I didn't understand what she meant by this. I'm guessing shading means you take make-up and go over a certain spot over and over again to make something less accented. But with 2AM's Changmin, you have to add it near his mouth because his mouth is known for sticking out. She continued, "One day, I saw him sleeping while getting his make-up done. While he was sleeping, the make-up artist finished the shading around his mouth. I know that he hates his mouth that sticks out." If you think about it, it's kind of funny. What's more awkward, to have someone pat stuff all around your mouth or to watch it happen?