What is the significance of Lennie’s two visions (Aunt Clara and the Giant Rabbit, both of whom speak in Lennie’s own voice)?
Lennie’s visions show how he (subconsciously) feels about the whole situation,
they say what he is afraid of – he feels he’s disappointed George (who deserves better than him) and that George is going to abandon him.
(Aunt Clara) "You never give a thought to George," she went on in Lennie's voice. "He been doin' nice things for you alla time. When he got a piece of pie you always got half or more'n half. An' if they was any ketchup, why he'd give it all to you."
(Giant Rabbit) But the rabbit repeated softly over and over, "He gonna leave you, ya crazy bastard. He gonna leave ya all alone. He gonna leave ya, crazy bastard."