This statement not only foreshadows Snowball's demonization but also predicts Napoleon's tyrannical rule which is vested in brutality, manipulation, exploitation, abuse and propaganda.
With Snowball out of the way, Napoleon can achieve sole leadership of the farm without being contested. Snowball had been a thorn in Napoleon's side. The two could never agree on anything and were consistently at loggerheads during meetings. Furthermore, Snowball had made a greater impression on the other animals especially with his plans for the erection of a windmill. He had also worked very hard at establishing committees and educating the animals. In essence, Snowball was working towards a greater good, whereas the sly Napoleon had only his own interests at heart. This was most aptly illustrated by his removal of Bluebell and Jessie's pups soon after they had weaned. He kept them in hiding and later used them to brutalise and execute any animal that dared oppose him.
Snowball became the scapegoat for everything that went wrong on the farm. It was put out, for example, that he had been in cahoots with Jones from the very beginning. After his expulsion, it was also said that he had surreptitiously been visiting the farm, destroying all the animals' hard work. Napoleon even went as far as sniffing out his scent and indicating signs of his so-called secret visitations. Snowball was thoroughly demonized through a process of propaganda and misinformation.
In pursuing this deceitful tactic, Napoleon had cleverly destroyed the animals' faith in Snowball and what he had stood for. By offering rewards for Snowball's capture and pronouncing a death sentence upon him, he created the illusion that he had all the animals best interests at heart. Although some animals had expressed misgivings about what they were told, the propaganda was so convincing that the unintelligent animals were easily swayed.
In addition, demonising Snowball and making him the enemy ensured that Napoleon could also purge the farm of all those who stood against him. So it was with the hens who refused to lay eggs for sale and a number of other animals who confessed to having secretly assisted Snowball. They were all executed when the dogs tore out their throats at Napoleon's instruction. This brutal act drove fear into the animals and they meekly and unquestioningly followed instructions.
Napoleon later assumed total control of the farm and was referred to as 'Our Leader, comrade Napoleon.' He and the other pigs practised human vices such as drinking alcohol and they became more human in their actions and demeanour. The pigs adopted a supercilious attitude and changed the commandments to suit them. Although there were murmurs of discontent at each alteration, these were soon suppressed by propaganda and lies as well as the threat of Jones coming back. it is no wonder then that the animals were even more enslaved, abused and exploited than in Jones' time.
A further point for consideration is the fact that the statement, 'Snowball's heroism is much exaggerated' also alludes to the animals own heroic attempts at achieving utopia. The grand purpose of their attempts was much exaggerated since their efforts ended in utter failure. They had not achieved their ideal and instead replaced one tyrant with another. Worse, still, is the fact that their new master was one of their own. Their current oppressor could not care less about their situation and used them to ensure privilege for himself and his own breed. Napoleon and the pigs lived lives of luxury and privilege, whilst the other animals suffered.
Tragically, life on the farm had gone full circle and the majority of the animals found themselves in an even worse situation than they had been under Mr Jones' rule.