I had photoshop open so I did this
The shape of the pot itself was based largely off 3 different ancient Greek pots and the patterning in the final image was also based off ancient design for both placement and design
Each of the pokemon in the giveaway were chosen to represent a Greek god or something from Greek mythos:
Primarina (Aphrodite), Decidueye (Apollo), Braviary (Ares), Lycanroc-Dusk (Artemis), Noctowl (Athena), Lilligant (Demeter), Roserade (Persephone), Dusknoir (Hades), Coalossal (Hephaestus), Thievul (Hermes), Blastoise (Poseidon), Chandelure (Prometheus), Liepard (Nemesis), Milotic (Iris), Cursola (Hecate), Magmortar (Hestia), Tsareena (Hera), Marshadow (Thanatos), Thundurus (Zeus)
The posing of the primarina with the shell (cursola) behind it is a loose reference to the Birth of Venus painting (same godess). The Roserade (Persephone) is the circles above Falinks and one in Dusknoir's stomage mouth, referencing the myth of her being in the land of the living for most of the year and in the underworld during winter. Demeter is the mother of Persephone so Lilligant's head flower is with Roserade above. Magmortar's stomach pattern is in the middle top of the right vase with the swirl on the back of Marshadow's hands on either side.