This article contains spoilers for "Batman v Superman: Dawn of Justice.
As the second film in Warner Bros. and DC Entertainment's new shared cinematic universe, "Batman v Superman: Dawn of Justice" does a lot to lay the groundwork for what's to come. In addition to introducing Batman (Ben Affleck) and Wonder Woman (Gal Gadot) into the world, it also features cameo appearances from Aquaman (Jason Momoa), Cyborg (Ray Fisher) and Flash (Ezra Miller). All three of those cameos come in the form of found footage on a LexCorp harddrive, which Batman and Wonder Woman individually watch during the film -- but Miller's Flash has another, more telling cameo earlier in the film.
Following Batman's hellish "knightmare" of a world overrun by Superman and his shock troops, a possibly-dreaming Bruce Wayne encounters a time-traveling Flash, who has run back in time to warn him of future events. "BvS" producer Deborah Snyder spoke to Collider about this development, saying that it was done to deliberately link to upcoming films.
“This was kind of the opposite [of 'Breaking Bad'] because we had the script and it wasn’t in the script," said Snyder, referring to "Breaking Bad's" penchant to take plot turns without knowing where they may lead. "As we started, then we worked on our script, I think we were in the middle of shooting and we started working on the outline for the next movie and where they go, and Zack said, ‘Oh my God let’s add this moment that is gonna pay off down the road, and we’ll find out more information.’” Flash is next expected to pop up in 2017's "Justice League" film, which will be directed by Zack Snyder and begins production in mid-April.
Snyder also saw an opportunity for a connection with the photograph from 1918 of Wonder Woman and members of that solo film's cast (including Chris Pine). Deborah Snyder revealed that the photo seen in the film was actually shot twice, updating it once they realized they could connect "BvS" to "Wonder Woman" with it.
“We just shot it and then when they were working on the script [for 'Wonder Woman'] we were like, ‘Wow what if we put in the script the actual taking of the photograph?’" said Snyder. "But it’s totally different people because we shot it on our set, so when ['Wonder Woman' director] Patty [Jenkins] was doing camera tests, we were back and forth because we were prepping that movie and editing and starting 'Justice League.' On one of the days we just got the group together, brought over -- because it’s shot on these beautiful glass plates -- we brought Steven over, who is a friend of Zack’s from Arts Center, he’s a professor over there and he shoots this beautiful glass plate photography, and we shot it with all the cast.”
"Batman v Superman: Dawn of Justice" is in theaters now; "Wonder Woman" opens on June 23, 2017 and "Justice League Part One" opens on November 17, 2017.