SPOILER WARNING: This article contains spoilers for "Batman v Superman: Dawn of Justice."
"Batman v Superman: Dawn of Justice" didn't show much of the other Justice League members, but it was enough to prompt a great many questions. In particular, Cyborg's file -- which included a brief video of Victor Stone's transformation -- left many wondering what, exactly, Dr. Silas Stone used to create the technology that would eventually save Vic's life.
"That's the first glimpse of the Mother Box there," Snyder revealed, adding, "It was an agonizing birth."
"I really wanted to show Cyborg's birth because I feel like he plays such a strong part coming up, and I really wanted to give a sense of him," he shared. "I really want [the audience] to know how far he's come."
In the comics, Mother Boxes are pieces of Apokoliptian technology. They serve a great many functions, including teleportation, sensing danger, sensing life, creating force fields, rearranging molecular structure of matter, absorbing or projecting powerful shock blasts and much, much more. Major villain Darkseid, whose impending arrival was teased all throughout the film, often uses the tech.
It remains unclear how Silas Stone got his hands on a Mother Box or how he was able to discover how it works. However, as Snyder suggests, it'll likely bolster Cyborg's connection to upcoming events in the DC Cinematic Universe.