Harsh Word
Othello chastises Desdemona in front of the Duke and Senators of Venice. His words are like a whip slashing across her every time she speaks. The imagery is so blatant that the Lodovico bids Othello to stop, but he won't and Desdemona leaves in tears.
Fight
Cassio is drunk and is challenging Roderigo for a fight when Montano tells him to stop. But he won't and he proceeds to attack Montano. This imagery represents the fact that Iago's plan is working perfectly by creating chaos and disorder in Cassio and among his fellow soldiers.
Wedding Bed
Othello enters the wedding bed to meet Desdemona by moving through a veil that covers the bed. The imagery represents the consummation of their love and that they have entered into a place that only they will be allowed entry for all their lives. The softness of this imagery is contrasted with the lies of Iago that causes Othello to believe his wife has betrayed him.
Suicide
Othello strangles himself to death after learning that Desdemona was innocent from Emilia and Iago was to blame. The imagery reveals the torture upon Othello's soul as he believes his afterlife must be tormented as he has taken the innocent life of the one woman he loved with all his heart. No other man must be charged with taking his life, it is his to claim for such a heinous crime against his wife.