In Chapter 8 of Animal Farm, what is the purpose of Napoleon's self-imposed sequestering and ceremonial appearances?
In Animal Farm, the animals start out with an ideal whereby they will be well-treated and there will be no more favoritism as "all animals are equal." However, the pigs soon set themselves apart despite the concept of Animalism which will ensure fairness and the commandments which support their dream. Gradually, the commandments are changed to suit the pigs' choices and to ensure that they enjoy comfort and control. Even Snowball, a "hero first-class" is chased off the farm and accused of sabotage because there can be only one leader and that is Napoleon.
In chapter 7, the animals are rebuilding the windmill during a hard Winter. There is talk of Snowball's sabotage and the hens "rebellion" which results in any animal that may have broken the rules being killed, including pigs. The animals are very scared and shocked at the apparent "execution of the traitors" which they have witnessed but this enhances Napoleon's position as protector. It is significant that, in chapter 8 when the animals consider the sixth commandment, the words "without cause" have been added to the rule that "No animal shall kill any other animal." The animals are therefore persuaded that Napoleon is their savior.
"Our leader, Comrade Napoleon" is very rarely seen in public and continues to increase in stature, becoming something of an enigma to the animals. He has more time to spend on his negotiations with the humans and keeps up the pretense that he has no intention of selling timber to "scoundrels." Prompted by Squealer's stories and accolades of Napoleon, the animals begin to imagine that he is responsible for any fortunate event and is even "the Father of All Animals."
The short answer to this question is that these things served to make Napoleon look more impressive and, thereby, to help him keep control over the rest of the animals.
You will have heard the phrase "familiarity breeds contempt." This is sort of the opposite. What Napoleon is trying to do is to keep himself aloof from all the rest of the animals so they will look at him as being above them. The same goes for all the ceremony -- it just serves to emphasize that Napoleon is not on the same level as the rest of the animals.
So, by doing these things, Napoleon enhances his image and his control of the other animals.