The word choice in the line, “When he saw these men and the object of their regard, his countenance fell. He glanced guiltily over his shoulder, and softly shut the door” expresses the of the excerpt:

once upon a midnight dreary, while i pondered, weak and weary,

explanation:

the anecdote makes readers feel sorry for the man’s lack of heritage, then reminds readers that the man has an equally valuable heritage.

normally working animals are domesticated and ruled by a master, a domesticator (tamer), to perform basic and important functions on a farm, for example. the value used in this context is animal labor in exchange for food. it is not so much a contrast to the story told by napoleon and the pigs, since the animals of that particular farm also performed functions on the farm through domestication. the only thing is that in this case, who rules them is a pig, also an animal, but very respected, to whom the other animals lent him submission. that's about a strong relationship of dependency between animal and owner.