How does the children's picture of Tim Johnson compare with Calpurnia's description of the dog when she calls Mr. Finch and Miss Eula May? Why does Lee include this event in the story?

Calpurnia is the first to recognize the serious nature of the situation, and she immediately makes the right phone calls, and runs to warn the neighbors. She protects many from danger, but receives no praise in comparison to Atticus who actually kills the dog. Though Atticus's skill with a gun is remarkable, Calpurnia's swift action and knowledge are invaluable. This is a reflection of how the black community's assistance to the white community in Maycomb is often unacknowledged.

Calpurnia is the first to recognize the serious nature of the situation, and she immediately makes the right phone calls, and runs to warn the neighbors. She protects many from danger, but receives no praise in comparison to Atticus who actually kills the dog. Though Atticus's skill with a gun is remarkable, Calpurnia's swift action and knowledge are invaluable. This is a reflection of how the black community's assistance to the white community in Maycomb is often unacknowledged.

I know this by heart because I've read this book so many times.