The photo, as it turns out, is really a piece of Deathstroke fan-art created by DeviantArt user jeransome, based on the previously-released test footage of Manganiello in costume.
Some pre-production work was clearly being done during the filming of Justice League on The Batman, as it was then that Affleck released test footage of a live-action Deathstroke, officially confirming that DC’s deadliest assassin would’ make an appearance in the Batman solo film.
A short while later, it was confirmed that Joe Manganiello would be playing the man under the mask, Slade Wilson, in Affleck’s movie.
Reports questioning Ben Affleck’s commitment to writing, producing, directing, and acting in his own Batman film might be prevalent, but by all appearances, production is moving steadily forward.