The cloak that covers Caesar's body assumes dramatic and powerful connotations in Antony's very carefully constructed funeral oration. Antony speaks at length from a raised platform, Caesar's body stationed below him. When the time is right, he moves down to Caesar's body and assumes a tone filled with memory and loss. He points out the cloak and speaks of the time when Caesar first wore it, on a summer night after Caesar had defeated one of Rome's enemies. Masterful. In doing these things, Antony has directed the crowd to look at Caesar's body, has played upon their emotions as Antony remembers a good time with his friend, and has reminded the crowd that Caesar was a victorious defender of Rome.
Once the crowd's attention has been directed to thecloak, Antony points out the various blood-stained tears in it where the conspirators' daggers had struck so violently. Now he has reminded them of the specifics of Caesar's brutal murder, making them imagine or relive the assassination as it took place. He also manages to work in the names of Cassius, Casca, and Brutus, thus identifying them personally as murders. During this recitation, his tone changes from gentle mourning to terrible outrage.
When he reaches an emotional crescendo and the crowd is deeply moved, Antony then dramatically pulls away the cloak to reveal Caesar's mutilated body. Antony's timing is deliberate and masterful. He uses Caesar's cloak, and then his body, as props in his funeral oration designed to sway the crowd against Brutus and the conspirators. He succeeds brilliantly, and civil war begins in Rome.
Marc Antony, despite his claims to the contrary, is a very gifted orator. He knows that the way to sway the plebians is to appeal to their emotions. One way to do this is to show them the cloak that Caesar was wearing when he was stabbed. He shows the crowd the bloody robe and holds it up, displaying the thirty-three stained holes. He talks about how each of those "honorable men" who ran him through must have had good reasons. Of course what he is really doing is suggesting that they had no good reasons and that they were not honorable men at all.
Finally, he chooses what is probably the bloodiest hole and tells the crowd that this is where Brutus stabbed his best friend. He calls it the "unkindest cut of all" since it was this cut, by a beloved friend, that peirced Caesar's heart and made him give up. With this visual aid, Antony effectively turns the crowd against Brutus, whom moments ago they were willing to crown emperor. Then, just as the crowd is beginning to realize the horror of this bloody murder, he rips away the cloak and reveals the actual gaping wounds in Caesar. Certainly this was done for effect--to whip the masses into a murderous frenzy.
Below is a link to Antony's speech and an analysis of it. I am also including a soliloquy, or solo speech, by Brutus and its analysis. This speech explains why Brutus feels he has no choice but to murder his friend, Caesar, whom he feels has become too powerful and corrupt, and a link to the analysis of several main characters. Good luck with your project!
Shakespeare used the cloak as a substitute for showing Caesar's body, which would have been nearly impossible on the stage with a mob standing in the way. Antony is able to raise the ripped and bloodstained clock high enough for everyone in the theater to see it clearly. The purpose was more to show it to the audience than to the mob. This is a case where a playwright used what is called a "plant." In Act II, scene 2, when Caesar decides to go to the Senate House he says
Give me my robe, for I will go.
But he and his companions do not exit immediately. There is more dialogue during which, presumably, a servant brings a robe or mantle or cloak and helps Caesar put it on. This robe is in good condition. A duplicate which is all torn and bloody will be shown to the audience, and they will naturally assume it is the same cloak they saw him put on at home and wearing in Act III, Scene 1.
The chances are that Caesar's body was not present at the funeral oration but only a dummy covered by a bloody cloak. Antony says the body is in a "coffin." So the dummy could be completely hidden from the audience after Antony removed the cloak. The mob members are supposedly looking at Caesar's hacked and bloodstained body, but they are only looking as a dummy, while Antony is holding up the substitute cloak for the audience to see.