This tone-establishing photo of Batman having a huffy little pout is apparently just the beginning of Warner's plan to build an entire superhero universe out of somber brooding. According to HitFix, multiple sources have claimed that the studio has issued a simple but extremely telling edict to all their DC movie screenwriters. "No jokes."
Though Zack Snyder's generally un-smirking self-seriousness has basically made that an assumed creed already, it seems it's no longer unwritten and is now the official mandate of the brand. So good news for those worried that Warner would try to shift gears to imitate Guardians of the Galaxy's success. But, of course, bad news for Aquaman, who now cannot respond to every plot point with a fourth wall-breaking "Somethin's fishy!"