How does the tone shift in chapters in which third-person narration is used?

In the second chapter of The Bean Trees, Barbara Kingsolver makes the one significant shift from Taylor's perspective in order to tell the back story of Lou Ann Ruiz. This is one of only two chapters in which Taylor does not appear and does not narrate; breaking from the first person perspective is perhaps the only way for Kingsolver to resolve the problematic dilemma of providing the volumes of information concerning Lou Ann Ruiz. Lou Ann certainly contributes to the pattern of women in the novel unjustly treated by men; her husband Angel, whose appearances in the novel are primarily recalled second-hand, is portrayed as an unstable and immature man bitter over his fate and unable to continue his relationship with a doting wife.