In “To Kill a Mockingbird” what “subtle change” does Scout notice in Atticus?

In "To Kill a Mockingbird," Scout notices a "subtle change" in her father Atticus after he takes up the case to defend Tom Robinson, a black man who has been falsely accused of rape. Scout sees that Atticus becomes more distant from his children and spends more time outside of the house. She is confused by this change in her father's behavior, but she eventually comes to understand that Atticus is simply trying to protect his family from the backlash that could come from him defending a black man in court.

Atticus' decision to defend Tom Robinson is a controversial one in Maycomb, a deeply segregated Southern town where racial tensions are high. Many of the town's white residents are angered by Atticus' decision to defend Tom, and they see it as an affront to the racial hierarchy that has been in place for generations. Atticus knows that his decision to defend Tom could put his family in danger, and so he becomes more guarded in his interactions with them.

Scout notices that Atticus is reading less and spending more time outdoors, as if he is preparing for something. She also sees that he is more distant with his children and less prone to play games with them. This change in Atticus' behavior is unsettling for Scout, but she eventually comes to understand that her father is simply trying to protect his family from the potential backlash that could come from his defense of Tom Robinson. This realization is a turning point for Scout, who begins to see her father in a new light and learns the importance of standing up for what is right, even in the face of great opposition.