From the artist’s comment:

I just needed something else to work on, so I threw this together. Based on “El Jucio de Paris” by the Spanish painter Enrique Simonet Lombardo [link] [artistic nudity] for those who wish to know the story. Basically caused the Trojan War in Roman mythology. This was mostly an exercise in putting together a background from scratch.

Opted to omit the togas, they just seemed to clutter things. The placement makes Rainbow Dash Athena; Applejack, Hera; Rarity, Venus/Aphrodite; Sweetie Bell, Cupid; and Spike, Paris. All in all, the characters matched up pretty well. Looking at it now, I’m worried that the eyes on Rainbow and Sweetie don’t quite look where they’re supposed to.

Sweetie Bell and sheep by me, everything else: [links at source – I’m not recreating all that.]