Final answer:
Romeo compares where Juliet lives to heaven.
Step-by-step explanation:
In this excerpt from Romeo and Juliet, Romeo compares where Juliet lives to heaven. He describes Juliet's residence as a place where every unworthy thing, including cats, dogs, and mice, can live and look upon her. By making this comparison, Romeo is expressing that Juliet's presence in that place is like heaven, as her presence brings him joy and happiness.