So the woman bought a swan who used to be a duck – also known as "a creature that became more than what was hoped for." The swan gets pulled away by immigration officials, and the old lady is left only with a swan feather that she hopes to one day give to her daughter. What does this all mean? Well, we would argue that Tan is making a really strong case for the swan/swan feather to represent all the best wishes and hope for a better life in the new world. Obviously the woman has hopes for her daughter (for her worth not to be "measured by the loudness of her husband’s belch" – yikes), but what the duck/swan represents is something greater than hope, something that exceeds the wildest imagination.