What does atticus see as a sign that perhaps things are beginning to change?

Atticus' sister, his children's aunt Alexandra, is staying with him and his children to help with the stress in the family, but ironically is doing the opposite. She is constantly criticizing him for things such as letting Scout wear overalls and talking boldly in front of Calpurnia. Scout sees change in his patience and the way he doesn't stand as tall anymore with the tremendous stress going on, as he works so hard for his kids to stay safe. I hope this answers your question.