Sal’s observation that Phoebe has “birds of sadness” in her hair suggests that Phoebe is actively choosing to be miserable and deny reality. Although Mrs. Winterbottom’s disappearance is upsetting, it’s implied that Phoebe has the power to choose to approach her mother’s disappearance in healthier way. This idea is contrasted with the allusion to Prometheus, a Greek god whom Zeus punished by sentencing him to eternal torture. Paired together, these details perhaps suggest that although suffering can seem never-ending, people can still choose how they respond to it.