In Act 4 Scene 3, What does the audience learn of Emilia? Does this change our opinion of Iago?

Desdemona asks Emilia whether she would commit adultery to win her husband the world. Emilia, the more practical one, thinks that it is not too big a price for a small act; Desdemona is too good, and too devout, to say that she would do so. It is implied that perhaps Emilia has been unfaithful. No, Iago is still a huge jerk no matter which way you look at him.