Juliet has an impatient yet pensive tone as she borrows from mythological imagery in the lines you mention. In this lesser-known monologue by Juliet, she waits for her new husband to come to her and consummate the marriage. Quite obviously, Juliet is impatient. She has to wait for night to fall, and it simply can't come fast enough. All of Juliet's images in her monologue revolve around this one theme. Most interestingly, however, Juliet borrows from Greek mythology to set the scene:
Gallop apace, you fiery-footed steeds, / Towards Phoebus' lodging! Such a wagoner / As Phaeton would whip you to the West / And bring in cloudy night immediately. (3.2.1-4)
What an interesting image to use, one that definitely has been given by an impassioned lover! Phaeton, of course, couldn't control the horses. Therefore, although, night might come faster, it certainly wouldn't come with any regularity or certainty. All of Juliet's other images here revert back to this image of night coming quickly. Juliet even uses apostrophe when she directly addresses night in her monologue. Juliet combines apostrophe with metaphor in a beautiful image describing her lover:
Come, gentle night; come, loving, black-browed night; / Give me my Romeo; and, when he shall die, / Take him and cut him out in little stars, / And he will make the face of heaven so fine / That all the world will be in love with night / And pay no worship to the garish sun. (3.2.20-25)
Oh, but the dramatic irony in this scene is enough to break anyone's heart! The audience knows that Romeo has killed Juliet's cousin, Tybalt. This murder will most certainly foul the lovers' chances to be together! Juliet, of course, has no knowledge of this until the Nurse tells her later in the scene. The audience, then, has no choice but to look on with sad eyes.