Athena and Poseidon. To find out more about the contest between Athena and Poseidon, see this Wikipedia article: link; for information about the image: image source.
You can see the rival gods Athena and Poseidon facing off here - Athena has her owl, of course, and Poseidon can be recognized his trident. Meanwhile, be sure to notice the female Sphinx on the pillar between them - quite an image! You can find out more about this Etruscan vase painting at this informative Louvre webpage.