The images depict what appears to be a casino, with the caption "Looks like a nice place for some R&R..." and a Krogan in full armor, accompanying the caption "Does not look like a guy you'd want to mess with..." Is this the anticipated DLC first hinted at in December? How does a casino fit into the Mass Effect universe?
It's "all hands on deck" as level designer Jos Hendricks posted a month ago, with it already confirmed that both Seth Green and Raphael Sbarge would be reprising their roles as Joker and Kaiden Alenko (provided you didn't... you know), but it seems we'll have to wait to find out who this potentially new, potentially dangerous Krogan is, and where this new location is found.
With no release date, and no further information besides a second tweet from Gamble simply stating "Enjoy your teasers. Two for the price of one ;)," potentially hinting that these are teasers for two separate expansions, only time will tell what's in store for Shepard and his crew.