What is a Spontaneous Demonstration? What is the purpose?

Napoleon now introduces a weekly event called the Spontaneous Demonstration, where every animal would leave their work to march in military procession around the farm, so as to instil pride in the animals in the achievements of the farm since the rebellion. It comforts the animals to know that, no matter how hard their lives, at least they have the benefit of being their own masters. Another consolation around this time is the reappearance of Moses and his tales of SugarCandy Mountain. Many of the animals like to believe that they will go to a better place after their deaths, and the pigs now seem to tolerate Moses, giving him an allowance of beer every day.