Napoleon and Snowball address leadership in several different ways. Napoleon uses propaganda, slogans, and force to get his way, while Snowball attempts to live according to the ideals that Old Major put forth. One obvious example is the windmill, which Snowball wants built to ease everyone in their work.
...thereafter, [Snowball] declared, so much labour would be saved that the animals would only need to work three days a week. Napoleon, on the other hand, argued that the great need of the moment was to increase food production, and that if they wasted time on the windmill they would all starve to death.
(Orwell, Animal Farm, george-orwell.org)
Snowball genuinely wants to use the farm's collective labor to improve the lives of everyone. He tries to convince the animals to take his side with logic and debate. Napoleon, though, understands that if the animals are not constantly beaten down with hard labor, they will start to actually demand the fair and equal environment they were promised, and he will be out of power; in the debate, he uses his trained dogs to run Snowball off the farm, increasing his personal power.
Leadership and power is seen amongst Snowball and Napoleon in varied ways. Snowball uses the power of speech to convice the animals into going with the plan of the windmill. However on the other hand we see Napoleon abusing power, calling out his dogs to attack on the snowball, this is seen as power of force.
Hope it helps. Im new to this and still a student so please do forgive me if this isnt quite helpful. Help you go well in whatever you are doing. Im the same grade as you :)