Analyzing Flashback in Plot Development

Read the following excerpt from a fictional narrative:

As the clock struck midnight, Emily found herself wandering through the abandoned corridors of her childhood home. The wood creaked beneath her feet, each sound echoing memories of laughter and tears. She paused at the old nursery, the wallpaper peeling like dried paint, remnants of a time long forgotten. In the corner, a dusty toy still sat, a stark reminder of her youth.

In the context of the story, how does the author’s use of flashback as a structural device influence the development of the plot?