In "Batman v Superman: Dawn of Justice," Diana isn't just an Amazonian princess -- she's also an antiquities dealer.
Even a princess needs to make a living in Man's World, and -- according to a description of the character that surfaced on Instagram -- she has rather appropriately chosen to become an antiquities dealer. After all, if the rumor that she's 5,000 years old by the time of the film pans out, she'll have lived to see commonplace items become antiques. This may also explain how she and Bruce Wayne meet in the film.
According to the character description on the packaging of a Wonder Woman bust,
The world's first and foremost female Super Hero, Wonder Woman at once embodies the unrivaled force and supreme grace of a born warrior, and the genuine compassion and understanding of a true humanitarian. As a symbol of equality, power, and truth, her natural confidence and unmistakable intelligence make her an unequalled, if unexpected, ally.
The immortal Amazonian Princess Diana keeps her eyes and ears open for intrigue as the beautiful and mysterious antiquities dealer, Diana Prince.