In depicting the pigs as friends--even playing cards with and getting drunk-- with the humans, who were the former enemy, Orwell suggests the failure of all such revolutions. They might begin with noble ideals, such as those Old Major articulates, but are corrupted by greed for power. When the animals look in the window, onto the sight of the pigs playing poker with the humans, they look from pigs to humans and humans to pigs, and cannot tell one from the other. This scene symbolizes the failure of the communist revolution and becomes a satire on Marx's statements about the need for the "dictatorship by the proletariat," for in life, as in the book, that dictatorship results in tyranny.
The pigs run the farm as old Mr. Jones did before the rebellion. Napoleon and the other pigs are walking around on two legs, herding the other animals with whips, and asserting that all animals are NOT equal, some are more equal than others.
They remove the hoof and horn from the flag and change the name back to Manor Farm, which was the name of the farm before the rebellion. They no longer refer to each other as comrades, meaning the rebellious age is over.
The pigs form a friendly camaraderie with their fellow farmers, drinking and playing cards with them as they discuss the issues of running a farm and dealing with animals.