Echion: A Young Bride, An Old Woman with Torches
Echion, or Aetion, lived around 350 BCE, according to Pliny. His paintings were highly valued and sold for considerable sums. Pliny mentions five of his works: Bacchus, Tragedy and Comedy, Semiramis Rising from Slave to Queen, An Old Woman Carrying Torches, and A Young Bride notable for her modesty.
There's some confusion about Echion's identity, name, and time period. Lucian of Samosata describes a painter named Aetion who lived much later, around the 2nd century CE. Lucian recounts that Aetion's painting of Alexander the Great and Roxana's wedding was so admired at the Olympic Games that one of the judges, Proxenidas, gave his daughter in marriage to the artist.
We don’t have much to go with to recreate his style. For these two subjects, which are similar to portraits, the Fayum paintings are a plausible base. The Aldobrandini Wedding is a depiction of a bride and her preparation, but it is a part of a Roman decorative frieze, and would be quite different from panel paintings.
Inspirations
Fayum mummy portrait in the Antikensammlung Berlin.

Aldobrandini wedding, Vatican Museum.