This is a basically a one-gag show, as some episodes sometimes are....this one simply being "how to shut up the fat sheep who constantly snores and is driving poor Shaun nuts." Eventually, Shaun, in trying to shut up the snoring, gets everyone involved whether they want to or not, including the dog and the farmer - in other words, the whole cast.
Anyone who gets annoyed at listening to loud snoring, or an automobile alarm which has trouble shutting off, is going to be in for it watching this animated short.
Overall, decent humor - especially the first half - but then the gag begins to war a bit thin and you can't wait for silence to finally prevail.