The windmill scene represents the different projects that were modernized in the Russian Revolution.Both from Animal Farm and the Russian Revolution, they both had projects that represented the manipulation that was put the animals/people on the farm/in Russia.
Boxer: I will work harder! We need to make the Windmill for Napoleon!
The Battle of the Cowshed scene was to represent the battle between the White and Red Army.Mr. Jones and his crew represented the White Army who was anti-socialism or anti-communism. The animals represented the Red Army who wanted and supported the communism/animalism of the farm/Russia.
The Battle of the Cowshed
The way Napoleon and Stalin are ruling can represent what can happen in real life with politics.This can happen when government has complete power or when something else in the basics of government have complete power.
Squealer: You must gives these milk and apples. We work so hard!
If you don't like or agree with what we do, you will be punished death!