What helped Scout "stand in Boo Radley's shows"?

Scout asks Boo if he'd like to say good night to Jem. Boo doesn't say a word; he just nods. Scout sees that Boo would like to reach out and touch Jem, and tells him he can. She shows him how to gently stroke Jem's hair. After Boo does this, she perceives that he wants to leave, and she leads him to the porch, where he asks her in a near-whisper, "Will you take me home?" She accepts, and allows him to escort her down the block, just like a lady should. She leads him home and he goes inside his house and shuts the door. The narrator, speaking as an older Scout, says she never saw him again.

Standing on Boo's porch, Scout look out over the neighborhood imagining how Boo must have seen it, and how, for all these years, he watched over "his" children.