This literacy is a narrative because the author presents herself as the victim.  In the passage the author tells us about her failed marriage with her husband.  She first tells us about how her husband used to say "Baby my life is an open book".  As time went by and her husband started drinking and becoming more angry his aphorism changed from "Baby my life is an open book" to "Never judge a book by its cover".  The change in aphorisms was used to foreshadow the husband telling the author that he once killed a man who raped a neighborhood girl.  The passage gets ironic when he tries to portray himself as the hero for killing the man while having the author trapped in the corner of the bedroom.