Bias is where someone gives there opinion. Like if someone said that they thought xboxes were cooler than PlayStations
The thing that happen between chapter 21 and chapter 22 is the tone permanently changes to a more cynical attitude and this is the significant structural shift. The answer to this question is which asking about what happen between chapters 21 and 22 is that the tone permanently changes to a more cynical attitude.
............rip...........