In Animal Farm can you describe the whisky incident? Why would Orwell make the scene somewhat humorous?

The whisky incident refers to the first time the pigs sample alcohol.  Orwell describes them in a sort-of blundering fashion; because the large amounts of alcohol they consumed has made them ill, the pigs begin to think they, and most importantly Comrade Napoleon, are dying.  Orwell may have used humor here to give the reader a chance to laugh at the pigs, to show us that the pigs are not infallible even though they have taken control over the farm and consider themselves the "brain workers."

A key significance to this moment is that the next day the pigs, of course, change the commandment which originally banned the drinking of alcohol by animals so that it included the phrase "to excess" - another blatantly corrupt use of the pigs' power.