What does the sinking bundle symbolize in inside out and back again?

The sinking bundle in "Inside Out & Back Again" symbolizes the loss and tragedy experienced by the main character, Ha, as she flees her home during the Vietnam War. It represents the destruction of her old life and the uncertainty of her future as a refugee in a new country. The sinking bundle also embodies Ha's struggle to let go of her past and adjust to the challenges of her new reality.