The quotation that is an example of foreshadowing is “The farmhouse should be preserved as a museum. All were agreed that no animal must ever live there”.
Foreshadowing is a literary device that the writer uses to give a hint of what is going to happen later in the story. In this case, the fact that “no animal must ever live there” gives the reader a clue that, at some point, this situation is going to change. Towards the end of the story, the reader learn that Napoleon and the other pigs finish living in the farmhouse that they had prohibited the other animals to live in.