Read the excerpt below and answer the question. Until now the animals had been about equally divided in their sympathies, but in a moment Snowball's eloquence had carried them away. In glowing sentences he painted a picture of Animal Farm as it might be when sordid labour was lifted from the animals' backs. His imagination had now run far beyond chaff-cutters and turnip-slicers. Electricity, he said, could operate threshing machines, ploughs, harrows, rollers, and reapers and binders, besides supplying every stall with its own electric light, hot and cold water, and an electric heater. By the time he had finished speaking, there was no doubt as to which way the vote would go. But just at this moment Napoleon stood up and, casting a peculiar sidelong look at Snowball, uttered a high-pitched whimper of a kind no one had ever heard him utter before. At this there was a terrible baying sound outside, and nine enormous dogs wearing brass-studded collars came bounding into the barn. They dashed straight for Snowball, who only sprang from his place just in time to escape their snapping jaws. In a moment he was out of the door and they were after him. Too amazed and frightened to speak, all the animals crowded through the door to watch the chase. Snowball was racing across the long pasture that led to the road. He was running as only a pig can run, but the dogs were close on his heels. Suddenly he slipped and it seemed certain that they had him. Then he was up again, running faster than ever, then the dogs were gaining on him again. One of them all but closed his jaws on Snowball's tail, but Snowball whisked it free just in time. Then he put on an extra spurt and, with a few inches to spare, slipped through a hole in the hedge and was seen no more.

In at least 150 words, explain how this scene signals a major change in the plot of Animal Farm.