"Mr Anderson thinks that everything inside of him is worthless and embarrassing".
"Dead Poets Society" is an amazing movie. It's one of those rare gems that is full of wisdom. Every scene has insights on life that can be useful to us all.
Robin Williams' character sees Mr Anderson's pain. He knows he feels worthless and ashamed of revealing himself to the world. And he knows that the freethinking that he can learn through poetry can change that and free him to become the beautiful person he is inside.
In this scene he first pulls Mr Anderson out of his comfort zone by making him stand in front of the class and "yawp". The kids laugh, he's embarrassed. But all that begins to change when Robin Williams' character makes him turn his back to the class and look at the picture of Walt Whitman hanging on the wall. He describes the picture of Walt Whitman as a "sweaty-toothed mad man". When Mr Anderson looks down from that picture his teacher makes it impossible for him to look at the class by circling him. His focus is no longer on his peers but on his teacher.