In contrast to the scene preceding this one, now we have another colorful and theatrical spectacle of yet another rich suitor who has come to try and outwit fortune and claim Portia for his bride.
As Morocco inspects the caskets, Shakespeare is able to inform the audience more fully of the details of the casket competition for Portia's hand. The casket that will win her contains a miniature portrait of her, and all of the caskets have inscriptions upon them, which Morocco reads for us. These inscriptions are important; each succeeding suitor will reflect upon them, and as he does so, he will reveal the truth about his own character. The inscriptions are, of course, intentionally ambiguous; they can be interpreted in more than one way. Remembering that this is a romantic comedy, we expect that Morocco will misinterpret them, as will Arragon later, and that finally Bassanio will read the inscriptions and interpret them correctly.
We should remember as we read this scene that Portia herself, at this point, does not know which of the caskets will win her. As Morocco moves from one to the next, Portia will be reacting on stage, silently revealing her thoughts, for she cannot guide Morocco, and we have some evidence for believing that Portia is not usually a quiet woman.
