What disappointment does Mabel share with Mrs. Bean during the scene in the cider cellar?

While Mabel is down in the cider cellar, she and Mrs. Bean continue to yell out to one another even though Mrs. Bean is still all the way upstairs. During this conversation, Mabel shares with Mrs. Bean that Bean had promised to give Mabel the fox's tail. When Mrs. Bean shares that the fox's tail has already been destroyed, Mabel is greatly disappointed.