What advantages does the sudden clear moonlight afford Maurgerite?

The moonlight affords Marguerite the chance to spend some time with her husband.

“The air is deliciously cool,” she said, “the moonlight peaceful and poetic, and the garden inviting. Will you not stay in it awhile; the hour is not yet late, or is my company so distasteful to you, that you are in a hurry to rid yourself of it?”