what is the purpose of aunt clara's appearance in lennie's mind's eye?

Emphasizing the delusional nature of Lennie's point-of-view, Steinbeck adapts his one experimental narrative gesture in the novel, choosing to depict two hallucinations - first Aunt Clara, and then (more ludicrous still) a giant sardonic rabbit. It is unclear whether we are supposed to understand these hallucinations to be one-time phenomena or regularly recurring. (By the way, the reader may find it a bit unbelievable that this gentle giant, who everywhere else proves incapable of understanding figurative language, is able to imaginatively generate such colorful self-chastisements as "you ain't worth a greased jack-pin to ram you into hell" (112).)

George Kills Lennie