What does Scout do on the Radley porch at the end of To Kill a Mockingbird?
Scout's standing on the Radley porch after having walked Boo Radley home metaphorically fulfills the maturation theme initiated by Scout's father in Chapter 3 when he instructs her,
"You never really understand a person until you consider things from his point of view--....until you climb into his skin and walk around in it."
Now, after all that has transpired, Scout realizes that she and Jem and Dill have not reciprocated for all that Boo has done for them--she considers things from Boo's perspective.
Atticus was right...you never really know a man until you stand in his shoes....Just standing on the Radley porch was enough.
As she walks home, Scout remarks that she feels "very old"; indeed, she has matured as she stands on the Radley porch. When she arrives at her house, her father has taken up The Gray Ghost, the third of a trilogy by Seckatary Hawkins, a book that contains an incident in which there is a character called Three-Finger Pete, a character not unlike Boo Radley. Ironically, Jem has won this book by going up to the Radley house, and now Scout returns from having stood on this very porch. This scene, too, ties together the entire narrative as it connects with one of the early chapters, both relative to the Radley porch. In Chapter 1 the children are engaged in a childish prank; in Chapter 31, Scout steps off the porch feeling "older" with new insights on life.
While standing on Boo Radley's porch at the end of Lee's To Kill a Mockingbird, Scout says the following:
I turned to go home. Street lights winked down the street all the way to town. I had never seen our neighborhood from this angle (278).
From this enlightening perspective, Scout imagines seeing the world through Boo's eyes on a regular summer day. She pictures him watching the ladies crossing the street to talk to each other. She even pictures him watching as she and Jem run to their father every evening when he comes home from work. Not only that, but Scout then envisions Boo watching events that happened in the fall and winter seasons and pretends to understand what he may have thought or felt during those times. She summarizes the whole book through the imagined senses of a man who once seemed like a ghost to her. Then Scout says something profound:
Atticus was right. One time he said you never really know a man until you stand in his shoes and walk around in them. Just standing on the Radley porch was enough (279).
So what is Scout doing on the Radley porch? She's soaking in Boo Radley's perspective and imagining his life as a witness to theirs. She's realizing that even though Boo seems to be a bystander, he nonetheless plays a role in her neighborhood's story. Therefore, by the end of the story, Scout has finally learned how to stand in another's shoes.