After being absent from the trailers and most other promotional material, the Man of Steel shows up to promote the JL movie. I mean - he’s clearly photoshopped in, so who knows. Maybe Batman just put together a thing on his Bat Computer to make it look like Supes is with them. :)
Also - where’s Cyborg going?
“Over there! Steppenwolf!”
“That’s a rock. Adjust your optical sensors!”