Lodovico
His presence is used to set the tone of the scene--he is the voice of Venice.
Othello
Othello is still the acting authority in Cyprus.
Desdemona
She is very concerned about how she is viewed--she know she s not a whore, and she is disturbed that anyone would think she was an improper woman.
Emilia
Emilia talks with Desdemona in the bedroom.

Emilia considers that Desdemona should challenge Othello. They speak of when and if a woman should cheat on her husband. Desdemona firmly believes there is never a reason to cheat on a husband.