Explain how the works of William Shakespeare influence the way that John frames his experience of seeing the sleeping Lenina? What is crazy about the way he perceives her?

John sees Lenina as "trustful" and "helpless". From the text:

"Her eyes, her hair, her cheek, her gait, her voice;
Handlest in thy discourse O! that her hand,
In whose comparison all whites are ink
Writing their own reproach; to whose soft seizure
The cygnet's down is harsh …"

A fly buzzed round her; he waved it away. "Flies," he remembered,

"On the white wonder of dear Juliet's hand, may seize
And steal immortal blessing from her lips,
Who, even in pure and vestal modesty,
Still blush, as thinking their own kisses sin.

It would have been crazy for John to describe Lenina, who was wanton, as "pure and vestal".