How does Neil Gaiman use imagery in Death, the High Cost of Living?

Imagery:

"Listen: One day in every century Death takes on mortal flesh, better to comprehend what the lives she takes must feel like, to taste the bitter tang of mortality: And this is the price she must pay for being the divider of the living from all that has gone before, all that must come after.
Haven't you ever heard that before?"
Chap. Three, p. 3