How and why is Animal Farm an unrealistic story?
There are lots of unrealistic aspects in Animal Farm. The notion that animals might talk and plan a revolution, for example, is completely unrealistic. Moreover, the idea that they might expel the humans and then take over the management of a farm is also unrealistic.
However, it is important to remember that Orwell never intended this story to be realistic. In contrast, he intended to write an allegory, a story with a hidden meaning. Specifically, he used this story to highlight the fact that the Russian Revolution did not have a positive effect on the people of Russia. In reality, it led to the dictatorship of Joseph Stalin and the slaughter of millions of innocent Russians.
In addition, Orwell never intended to create realistic characters. He deliberately created caricatures of real historical figures. Old Major, for example, is a symbolic representation of both Karl Marx and Vladimir Lenin because he provides both the ideological impetus and the practical inspiration for the revolution. Similarly, Snowball is a symbolic representation of Leon Trotsky, while Napoleon represents Joseph Stalin.
By creating these caricatures, Orwell encourages the reader to look deeper to gauge the story's real meaning.
Animal Farm is an unrealistic story because it is about animals that plan and execute a revolutionary rebellion against their human owners/rulers.
It is also unrealistic because it has animals forming a governing ideology called "Animalism." It's a lot like communism, which is real, but animals forming a society based on an ideology and drafting commandments to live by is definitely what I would call unrealistic.
The story continues its unrealistic characteristics by having the animals talk to each other, gesture, and express human emotions. They plan to build windmills and other forms of infrastructure too.
It's also unrealistic for pigs to begin walking on two feet and wearing clothes like humans.
The story is not meant to be taken at a literal level though. Animal Farm is an allegorical commentary on the communism that was happening in Russia. One thing that an allegory will do is take specific characters or situations and have them stand in for other characters or situations in order to make a point about them. That's what Animal Farm is doing, and the point it's making about communism is not a glowing endorsement of that system of government.