I think he wants to tease and build interest but not spoil so he showed a low-res image to just confirm the new SW.
I was also disappointed by the SW design. Face looked ok in some scenes and stills. It was the motion that was seriously lacking. Cartoonish. I've said before that the speaking face moved too slow. I've played it at 15% faster and it works better.
The armor was not well thought out IMO. Looked very stiff and glued-on, unnatural.
Now we know why...
WB was too fraidy-scared. They wanted to try and chase the Marvel train and mis-understood the complaints and listened to a vocal minority.
Marvel killed Trillions. They destroyed worlds. They killed lots of people with extreme prejudice... but since there was not an outcry of the wreckage and "people" say Marvel films are better and "FUN" WB saw it as the way to go. But they took the wrong cues and went TOO far.
WB thought if they eliminated the "threats and damage and added "out-of-place humor they could chalk up a Bill- win.
They took away the danger, fear and reason for the hero's to act. They homogenized the story and made it a G rated film. WB apparently still does not know its audience.
I am not saying Snyder is everyone's cup of tea and even if the details can be debated, at least it was a well thought out vision...