In the context of the essay, who is in control: the police officer or the crowd? How are people influenced by the power they have over others? How are people in power forced to maintain a reputation? What is the cost of this?

The crowd is in control. The police officer makes the decisions he does in order to placate the crowd. Orwell believes that he must command the crowds respect by reacting appropriately to his position, regardless of the fact that he acts in oppositions to his own beliefs.