Though it’s a key sequence to the future of the DCEU, it was not originally part of Wonder Woman’s story; in fact, the film has no major deleted scenes.
She then shows the team a sketch of the object, which resembles a Mother Box from Apokolips — thus setting up the events of Justice League.
Patty Jenkins only decided to include it on the home release as a way to get the band back together, tease future adventures, and include some extra content for passionate fans.
The scene in question takes place in the immediate aftermath of Wonder Woman, as Etta Candy meets Steve Trevor’s former comrades and informs them that they have orders to retrieve a mysterious and powerful artifact discovered after a battle.