How does Orwell represent the relationship between greed and power?

Napoleon's power enables him to take advantage of those beneath him. The pigs, as the most intelligent animals, are able to manipulate the others into doing their bidding, all while keeping the advantages and wealth the others work so hard for to themselves. In essence, the animals' lives never really change... their perspective changes. The pigs, on the other hand, better their own lives without labor at the expense of others.