In Toni Cade Bambara's short story "The Lesson," the main character, Sylvia, is a dynamic character, not a "mouthpiece" for the author. A dynamic character is a...
...developing (dynamic) character
...a literary or dramatic character who undergoes an important inner change....
This story is the author's soap box; she's not preaching. The first thing to note about the story is that a great deal of inference is taking place. We are never told, as readers, what to think. We have to draw some conclusions as to what has taken place in the story. The author does not spoon-feed the reader, but provides stark contrasts between the lives of the rich white people who can afford to buy a toy sailboat for a thousand dollars ("one thousand one hundred and ninety-five dollars"), while the parents of these poor black children must scrounge and save to buy bunk beds for their kids.
We can see that Sylvia is a dynamic character because she is learning a lesson, though she tries hard not to:
"Watcha bring us here for, Miss Moore?"
"You sound angry, Sylvia. Are you mad about something?" Givin me one of them grins like she telling a grown-up joke that never turns out to be funny. And she's looking very closely at me like maybe she plannin to do my portrait from memory. I'm mad, but I won't give her that satisfaction. So I slouch around the store being very bored...
The reader must draw inferences here. The children have been taken to a very expensive toy store where they could never afford a toy. They are in an alien world; they cannot understand this kind of wealth. Sylvia gets the idea that there is a message Miss Moore is trying to share, but she is resentful—even she doesn't understand why. Miss Moore sends a pointed look at her, hoping to see Sylvia's "ah-ha" moment. Sylvia, however, is still fighting "the lesson."
Sylvia is a dynamic character because she has depth and she is going through a change:
...what's there to be afraid of, just a toy store. But I feel funny, shame. But what I got to be shamed about? Got as much right to go in as anybody. But somehow I can't seem to get hold of the door...
Sylvia knows in her heart that something is wrong: that society did not allow for someone like her (poor and black) to shop in that store. She insists she has done nothing to be ashamed of, and she has not; but her reaction comes from unfair limitations placed on the poor by the rich; on the blacks by the whites.
Miss Moore never does the thinking for the children. She presents an idea and gives them the opportunity to work it through. She says:
Imagine for a minute what kind of society it is in which some people can spend on a toy what it would cost to feed a family of six or seven. What do you think?
One of the girls thinks, "White folks crazy."
...this is not much of a democracy if you ask me. Equal chance to pursue happiness means an equal crack at the dough, don't it?
Miss Moore waits for Sylvia to articulate her thoughts, but Sylvia still fights it. However, as the children depart, we can infer that she did "get it." She walks as Sugar runs ahead; Sylvia wants to "think this day through."
[Sugar] can run if she want to and even run faster. But ain't nobody gonna beat me at nuthin.
The author simply allows a youngster to work through to the truth. Sylvia is a solid, credible character who is beginning to see the world through a different "lens." She will find "fair" in the world.