What objects are disappeared in Chapter 25 and how does this disappearance differ from all previous disappearances?

The narrator reveals in Chapter 25 that when she wakes up one morning, she knows that another object has been disappeared. She thinks to herself that she needs to hurry to catch the tram, since on the mornings of disappearances, the commutes tend to get chaotic. When she sits up in bed, however, she realizes that there is a large, heavy, unwieldy object attached to her left hip. Gradually, the reader comes to realize that everyone's left legs have been disappeared in the night. This is the first disappearance since the old man's death and it is clear that the stakes have now been raised in the disappearance department.