What does George Orwell's "Animal Firm" mean for you?

  I have tasted or read some Great Books in literature of humans' world. Among them, of course, "Animal Firm" by George Orwell is absolutely and significantly included. I have firstly read this book in Burmese translated version; then, some book reviews. Any part of it, whenever I read, it is one of the greatest creations in the field of mankind's literature.

When I read the book for the first time and talked around about the meaning of the book with my friends or co-readers, most of them said that it was about Soviet Union (no more or less than following systematically creative TRENDS just like millions of many others); some of them said that it was about Burma; while very few said the true meaning of the book was based upon neither Soviet Union nor Burma but something in humanity. 

Alright. If you look at the time Orwell wrote the book, 1943-44, it was absolutely not about Burma because Burma was not even an independent country yet. Then, was it about Soviet Union? Not really yet! The union itself was in still struggling period during world war II. Not really in the luxurious stages at all, even for its leaders. I mean they may be aggressive but not in luxury at that time at all. Another greatest interesting part is - to answer this question - why were protagonists of the story metaphoric to Pigs? Please take a look the final three paragraphs of the story; and let me ask you again - what is true meaning of "Animal Firm"?  When you find the great answer, you could surprisingly discover that by yourself or You Are Living In It (right now)!
(I will discuss about this later.) (Please read more carefully the Last Paragraph and the Last Sentence of the Story!)

There was the same hearty cheering as before, and the mugs were emptied

to the dregs. But as the animals outside gazed at the scene, it seemed to them

that some strange thing was happening. What was it that had altered in the

faces of the pigs? Clover's old dim eyes itted from one face to another. Some

of them had five chins, some had four, some had three. But what was it that

seemed to be melting and changing? Then, the applause having come to an

end, the company took up their cards and continued the game that had been

interrupted, and the animals crept silently away.

But they had not gone twenty yards when they stopped short. An uproar of

voices was coming from the farmhouse. They rushed back and looked through

the window again. Yes, a violent quarrel was in progress. There were shoutings,

bangings on the table, sharp suspicious glances, furious denials. The source of

the trouble appeared to be that Napoleon and Mr. Pilkington had each played

an ace of spades simultaneously.

Twelve voices were shouting in anger, and they were all alike. No question,

now, what had happened to the faces of the pigs. The creatures outside looked

from pig to man, and from man to pig, and from pig to man again; but already

it was impossible to say which was which.