Final answer:
Madam Loisel undergoes a transformation throughout the story, from dissatisfaction to joy to regret. This transformation highlights the theme of materialism and appreciating one's life.
Step-by-step explanation:
Madam Loisel undergoes a significant transformation throughout the story. Before the party, she is dissatisfied with her life and dreams of a more luxurious existence. During the party, she is vibrant and joyful, enjoying the attention and admiration of others. However, after the party, she realizes the necklace she borrowed is lost and spends years working to repay the debt. This transformation is tied to the theme of the story, which emphasizes the dangers of materialism and the importance of appreciating one's current circumstances.