I liked that during Mark Antony's speech, the camera cut to the blind soothsayer in the back of the crowd but in the foreground of the scene. He's an observer of the chaos that he knew was coming, and in plain view for us so that we can see the speech from his point of view.
(How do you think the blind soothsayer compares to Time/Antigonus in The Winter's Tale? Both characters are like the omniscient observers who only briefly intervene, and then let the events run their course.)
And we're back to the mob mentality. From Brutus' words, the crowd believes Brutus and the other "noble men" had to do what they had to do. But then when they actually see Caesar's bloodied body, the significance of what just happened really hits home.
Oh, that was sneaky: after Mark Antony riles up the crowd, and he turns to go back into the palace, we see a slight smile on his face. So does he have some sort of maligned motivation (or "ambition") after all?