Answer:
The answer above is correct: he reader understands the history of the rebellion, but the new horses do not.
Step-by-step explanation:
Animal Farm is a novella by George Orwell in which he uses allegory to criticize the Russian Revolution of 1917. The animals of a farm choose to expel the human owner and take over the farm. In the beginning, their goal is to live in an equal society, where no one rules and every one works in favor of every one. Such an ideal caves in when the pigs, the most intelligent animals, realize the advantages of being in power. With time, they start to oppress the other animals and spread falsehoods to keep them ignorant to reality.
That is precisely what is being described in the excerpt we are studying here. The new horses are not told the truth. The irony is in the fact that the reader knows how bad the real situation is while the horses don't.