In the story, two sisters represent contrasting strengths. One sister is strong, made of iron, while the other lacks physical strength. The strong sister ventures out into the rain but discovers her resilience is undermined as she rusts. This symbolizes that strength alone isn't enough to withstand challenges.

Conversely, the sister who isn't strong finds her way in the storm by offering warmth and support through a hug, ultimately showing that emotional connections and support can bring healing. This illustrates the theme that true strength lies in the ability to care for others in times of need.