Why did Moewenna get upset when she saw the painting Catherine was doing on her wall in Catherine Called Birdy?

Moewenna got upset when she saw Catherine's painting because it depicted a scene that was deeply personal and resonated with her own emotions. The painting reminded her of her past and the struggles she faced, making her feel vulnerable and exposed. Additionally, she may have felt that Catherine was expressing feelings or experiences that Moewenna was not ready to confront or share, leading to her distress.