Wonder Woman discovers an ancient painting of Darkseid as a speech made by Jesse Eisenberg's Lex Luthor from 2016's Batman v Superman: Dawn of Justice plays. Darkseid then appears amid a fiery background.
Darkseid was not featured in Whedon's Justice League.
Snyder, who helmed 2013's Man of Steel and Batman v Superman: Dawn of Justice, suffered a family tragedy when his daughter died by suicide after principal photography was finished on his version of Justice League. Whedon was then hired to write and direct reshoots.
Zack Snyder's Justice League, which will feature new scenes and a different story, is coming to HBO Max in 2021. Ben Affleck as Batman, Henry Cavill as Superman, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg and Amy Adams as Lois Lane also star.
Snyder also said on Twitter that fans can expect to learn more about the film at DC FanDome, an upcoming virtual event that will take place on Aug. 22. The event will have new footage and announcements for other DC films Wonder Woman 1984, The Batman and more.