What changes does Napoleon make immediately after the expulsion of Snowball? How do you interpret the effect of increased power on Napoleon?
Well, the first change Napoleon makes is to cancel the meetings held on Sunday morning. Immediately following, he starts having private meetings with just the pigs.
A bit later, Napoleon announces that they will build the windmill, finishing a project that had been cancelled.
Later still, the work week goes up, and after that, the changes are too distant in time and pages to be called immediate.
As far as how I interpret the effect, the main effect is that the use of force is openly threatened and that history is more actively rewritten to justify changes.