What does the metaphor romeo uses in so shows dove trooping with crows when he describes Juliet?

In Shakespeare's Romeo and Juliet, Romeo compares Juliet to a dove among crows when he first sees her at the Capulet ball. He says, "What lady's that, which doth enrich the hand / Of yonder knight? O, she doth teach the torches to burn bright! / It seems she hangs upon the cheek of night / Like a rich jewel in an Ethiope's ear, / Beauty too rich for use, for earth too dear!" (Act 1, Scene 5, lines 46-50).

This metaphor suggests that Juliet is pure and innocent, like a dove, while the other women at the ball are like crows, which are often seen as symbols of darkness and evil. Romeo is immediately drawn to Juliet's beauty and sees her as something special and unique. This comparison also foreshadows the tragic events that will follow, as Juliet's beauty will eventually lead to her downfall.