How is the first flash back effective in a text what inside does it provide and recourse larger scope of the story support with textual evidence

The first flashback serves to draw our attention to the young girl..... the little girl that causes Death to remain and watch, something he never does.

I studied the blinding, white-snow sky who stood at the window of the moving train. I practically inhaled it, but still, I wavered. I buckled—I became interested. In the girl. Curiosity got the better of me, and I resigned myself to stay as long as my schedule allowed, and I watched.