Prometheus was the Titan protector of the humans who gave the forbidden gift of fire to the human by stealing it from the Gods and was punished to live an eternity of torments of dying everyday devoured by an eagle that ate his liver day after day since he was inmortal.
Pandora was a woman created by Hephaestus. Zeus ordered Hephaestus to mold her out of earth as part of the punishment of humanity for Prometheus' theft of the secret of fire. Zeus wanted Pandora to open a Jar (nowadays referred as a box) that contained all the plagues for humanity.
The symbolism is that humans have been punished for their ambition and greed by the Gods in Greek Mythology.