In Act 3 Scene 4, What are two possible answers for the purpose of the short scene between Cassio and Bianca?

Cassio's behavior toward Bianca is in sharp contrast to the courtly politeness he shows Desdemona and Emilia. This is because of Bianca's station as a courtesan; such women were not accorded the same respect as ladies, although Bianca proves to be as perceptive as Emilia and Desdemona, and even more realistic about matters of love. The change in Cassio's tone and behavior around Bianca betray a cultural bias of the time toward women of certain stations; indeed, his behavior would not have been thought mean at the time, because of Bianca's lowly status.