Why does the author include details about the purchases the Lin family makes at the rummage sale in “The All-American Slurp”?

"as patricia rolled her eyes, dave stared at her, trying to discern whether she'd been lying. ' that stuff about the sleepwalking. was true? ' 'oh yeah,' carlos said, shaking his head. 'whole town seems to be coming down with it.' he paused. 'you're not scared of the dark, are you? ' what feeling does the author create by ending the story with this question