In the DCEU’s main timeline, there’s a well established connection between Ben Affleck’s Bruce Wayne and Ezra Miller’s Barry Allen. The latter showed up in a bizarre Batman V Superman: Dawn of Justice cameo to warn Bruce about events that were never actually followed up on, while in Justice League, the billionaire vigilante is positioned as a mentor of sorts to the Scarlet Speedster.
The relationship is going to factor even more heavily into The Flash as well, which will see Affleck make his grand return to the DCEU, although he won’t be the only Caped Crusader involved, with the multiverse also granting the can’t miss opportunity to have Michael Keaton suit up as the Dark Knight for the first time in almost 30 years.
Of course, Matt Reeves’ The Batman will exist in a separate corner of the franchise outwith the regular continuity, but recent set photos hinted at the tantalizing possibility that Superman exists in the same universe as Robert Pattinson’s rookie crimefighter. Not only that, but a new image has now teased the possibility that the Flash is also out there somewhere beyond the city limits of Gotham, which you can see below.
The fact that the the Scarlet Speedster’s signature symbol is featured on a tattered poster makes it clear that we shouldn’t be expecting any sort of substantial involvement, and these could well just be background Easter Eggs for eagle eyed fans to try and spot when The Batman eventually hits theaters in March 2022. However, it’s interesting nonetheless that Reeves is making a deliberate effort to include references to other DC heroes in a reboot that’s being positioned to tell a more standalone story than the rest of Warner Bros.’ comic book output.