A lightbulb appearing above someone's head meaning “I have a great idea” is because, A) a bright image like a lightbulb is a metaphor of a bright idea, a good and smart idea. ... So when someone has a bright idea, they're having an Edison moment, like Edison's bright idea of the bright lightbulb.
The store is a happy place for her and wants to give that impression to the reader. What impression does the author give of the store in "The Corner Store"? that he loves children and always remembers their weight and seemed to know exactly what they wanted.
The answer is independent clause