An example of the adult Scout commenting is when she explains that Atticus and Jack wanted her to hear their conversation.
To Kill a Mockingbird is narrated by Scout as a child, but Scout is telling the story from memory as an adult. After Jack spanks Scout for swearing at Francis, she tells him he needs to listen to both sides. Jack and Atticus have a conversation about Tom Robinson’s defense.
But I never figured out how Atticus knew I was listening, and it was not until many years later that I realized he wanted me to hear every word he said. (ch 9)
When Scout is listening in on the conversation between Uncle Jack and Atticus about the Tom Robinson trial, she is a child. When she reflects on it, she is doing so as an adult because she says “years later.”
In many ways, the entire narrative is from an adult perspective. Adult Scout just tries to share young Scout's thoughts. Yet occasionally the adult narrator intervenes and editorializes so the reader can fully appreciate and understand what is happening, even when young Scout is too young to really appreciater what is happening and its effects.