A new Mass Effect 3 screen is likely the first from the game's next piece of single-player DLC. Previous indications that the DLC would further explore the Citadel seem likely given a new shot tweeted by executive producer Casey Hudson. Another image tweeted minutes later by producer Mike Gamble shows a hammer-wielding Krogan taking the fight directly to your face.
The next single-player DLC remains unnamed and unannounced by BioWare, though numerous reports indicate that this addition will likely be larger than From Ashes, Leviathan, and Omega, with the full DLC writing staff involved.
Seth Green and Raphael Sbarge, Joker and Kaidan Alenko's respective voice actors, have both been confirmed back in the recording studio, and series composer Sam Hulick is also at work--all presumably for this content.
We don't know if both screens depict the same content, or if perhaps the Krogan Hammer Bros. will appear as a new class in upcoming multiplayer DLC.