Answer:
With the excerpt shown in the question, Juliet reveals that she has doubts about her love for Romeo, because everything is happening so fast.
Step-by-step explanation:
In this excerpt, Juliet shows how much she is in doubt and afraid about how fast her marriage to Romeo is coming to fruition. Juliet loves it, Romeo, that is a fact, but he fears it is birdlike because it is so sudden and hasty. It compares the common lightning situation where it suddenly happens and in seconds it is no longer there.
With this success, Shakespeare managed to convey to the reader the sense of apprehension and fear that Juliet is feeling. In this story we see that Juliet is a little mature and begins to think of this marriage with a little more rationality and a little less emotion. However, Juliet's feelings are stronger than reason, and as you already know all these thoughts are abandoned in favor of her love for Romeo.