We already know Batman v Superman: Dawn of Justice will feature Wonder Woman and include cameos by Aquaman (Jason Momoa) and Cyborg (Ray Fisher). But that’s not the only Justice League cameo we can look forward to. Hey, it’s not subtitled “Dawn of Justice” for nothing.
Costume designer Michael Wilkinson revealed the cameo — as well as an explanation of that tense first clip — in an interview with Brazilian news site Omelete. Consider everything from here on out to be a bit spoilerish.
“I’m not really at the liberty to talk about The Flash right now, but it’s something that you’ll be seeing in the future in our films. You do get a glimpse of him, of course, in Batman V Superman. [… Ezra Miller is] an extraordinary performer, he has a sort of interesting sense of humor and the youth that will be great for Barry Allen and I think he’s going to make a great Flash.” (translated by We Got This Covered)