Why is Lenina's looking at the moon important?

In literature, the moon usually symbolizes mystery and
imagination.

Here's examples of the moon connected with
Lenina:

• The moon is first mentioned early and
  connected with how she was sleeptaught as a child about Epsilons: "Even Epsilons are
  useful."


• Later, Huxley says Lenina is appalled by the
  pale face of the moon.


• She mentions the moon and sea on
  the date with Bernard.


• Franny's face is described as
  "moon-like."

Huxley is trying to show that
Lenina has no sense of mystery and imagination.  Her memories are vague and empty.  She
is pulled in no direction.  For her, the moon has lost its symbolic value.  To her, the
night is simply night, and the moon is simply the moon.  There's no mystical or
religious attraction to it for a Beta like Lenina.

However,
the moon is still important to the Savages, especially John.  John will eventually be
Lenina's moon: he will give her a sense of mystery and imagination when they meet in the
second half of the novel.