Throughout the course of Orwell's novella Animal Farm, we witness the gradual corruption of the ideals set forth by Major in the opening chapter.
In Chapter 1, when Major has the animals assemble in the barn to hear of his dream, Orwell tells us that the dogs came in first, followed by the pigs. The winged animals are mentioned next and then we hear that the cows and sheep positioned themselves behind the pigs. Finally, we see the horses, a goat, and a donkey. Orwell also describes some orphaned ducklings who take refuge near the female horse named Clover.
By Chapter 5, however, the seating arrangement has changed.Now, the leading pigs sit in front of the other animals on a raised platform, literally showing their elevated status above the other animals. The pigs are encircled by a protective ring of guard dogs. The other pigs sat behind the guard dogs, and then the "rest of the animals sat facing them in the main body of the barn."
One of the motivating factors behind Major's ideals had been to unify the animals, but gradually they were becoming more divided into various classes. Thus, I consider Orwell's most striking comment on this arrangement to be:
"Nowadays they did not sit all together as they had done in the past."