Explain the meaning of the quote below from Orwell's Animal Farm."The creatures outside looked from pig to man, and from man to pig, and from pig...

This quote comes at the end of Orwell's work.  In this
setting, the animals have gathered around the farmhouse to watch the dining/ celebration
between the humans and the animals.  As they heard Pilkington's toast and Napoleon's
follow- up toast, the celebration and drinking revelry took the animals back to an
extent.  Surveying the room of  and humans, the animals on the outside could not tell
the difference between the beings on the inside.  This helps to bring out Orwell's
fundamental point that politics and the constructs of power are universal, and that
those in the position of power have only one primary concern and that is not losing it. 
Both the humans and the pigs have found their common ground, which is being able to
exploit their workers and become masters of their respective universes.  When the
argument over the card game breaks out, the animals look again and see all of them
inside, no different from one another.  The dynamic of "insider" and "outsider" has made
those who have power, regardless of animal or human, those who are in control and those
who do not have power on the outside looking in.  Orwell's main point is to draw the
distinction here that "the twelve voices shouting" were not representative of the
animals' interest, but rather in protecting their own share and their own hold on
power.  There is no more of "animal vs. human" or "Animalism."  There is only power and
those who have it are inside the farmhouse and those who don't are on the outside of
it.