In the beginning of the story, Lizabeth and her friends always loved to bother and tease Miss Lottie. They would throw pebbles/rocks, yell and curse at her from the street, and destroy or damage her marigolds. This cell shows Lizabeth throwing a small rock at Miss Lottie's house, like they would do in the story.
Towards the middle of the story, Lizabeth was invited by her friends to go bother Miss Lottie. While the kids were collecting stones to throw, Lizabeth was hesitant to join in. The child in her thought it was all in good fun, but the other side of her disagreed. Eventually, she gave in and threw the rocks at the marigolds. This is what this cell is replicating.
Fueled by rage, spite, and confusion, Lizabeth destroyed Miss Lottie's marigolds, completely uprooting and ruining them. After this event, Lizabeth no longer saw Miss Lottie as an old witch and instead as a, "..broken old women who has dared to create beauty in the midst of ugliness and sterility." This cell shows Lizabeth crying like she was when destroying the marigolds and thinking about what happened. This is when she realized she is no longer a child.