Final answer:
Medusa was originally a beautiful young woman with golden hair but was transformed into a Gorgon with snakes for hair and a petrifying gaze by Athena, illustrating the contrast between her prior beauty and subsequent monstrous form.
Step-by-step explanation:
The characteristics of Medusa before and after her transformation are strikingly different. Initially, Medusa is described as a beautiful young woman with golden hair, exuding pride and attracting the envy of the goddess Athena. Her hubris in comparing her beauty to that of a deity leads to her downfall, with Athena transforming her into a Gorgon. After this transformation, Medusa's appearance becomes the stuff of nightmares: a hideous, evil creature with snakes for hair and a gaze that petrifies anyone who looks at her. The change from beauty to horror emphasizes the Greek gods' harshness and the theme that even physical symmetry, as expressed in artworks like the pedimental sculpture, cannot mitigate the terrifying power and innate ugliness of Medusa's cursed form.