The motif is in reference to Bertel Thorvaldsen and Pietro Galli: Jupiter’s Eagle and Psyche, 1838.
Psyche is kept captive by Venus, and is in the hands of Venus’ handmaids Worry and Sadness. Psyche escapes the monsters as Jupiter takes pity and sends an eagle to bring her water from the river Styx, as this is the third of four trials set by Venus.
“For Psyche’s third task, she is given a crystal vessel in which to collect the black water spewed by the source of the rivers Styx and Cocytus. Climbing the cliff from which it issues, she is daunted by the foreboding air of the place and dragons slithering through the rocks, and falls into despair. Jupiter himself takes pity on her, and sends his eagle to battle the dragons and retrieve the water for her”.