The pictures were produced by Ansar al Sharia's official media wing and then distributed on Twitter and other sites. It's official Twitter account was recently suspended by the social media site, as such its followers were responsible for the dissemination of these photos.
These photos show several fighters operating a checkpoint near the western entrance to the city. More than a dozen fighters are shown, including some manning technicals (heavily armed pickup trucks). One fighter is providing over-watch with a light machine gun on the roof of a building. At least three US-made Humvees are seen at the checkpoint. These vehicles were likely taken from Khalifa Haftar's forces.
It is also important to note that while the Islamic State-style of the "Black Standard" flag is shown, this does not necessarily mean affiliation. That style of flag was first popularized by al Qaeda in Iraq and then spread to other al Qaeda branches like al Qaeda in the Arabian Peninsula and al Shabaab in Somalia. The other common style of the "Black Standard", similar to the one used by al Qaeda Central, the Al Nusrah Front (al Qaeda in Syria), and a slew of other groups, is also seen.
This checkpoint shows that the group is consolidating its grip on the areas it controls in Benghazi. The group is thought to control a significant portion of Benghazi, this comes after months of fighting in the city after the aforementioned Khalifa Haftar initiated an offensive to "cleanse" Benghazi in May. The offensive reached a stalemate when Haftar initiated a renewed offensive in late Oct.
Ansar al Sharia plays an integral part in the al Qaeda network in Libya. I have previously outlined the groups al Qaeda connections in very thorough report broken down into two parts. Please read my reports, Ansar al Sharia and al Qaeda and More Proof of Ansar al Sharia's al Qaeda Connections. Moreover, my colleague Thomas Joscelyn over at The Long War Journal has written a plethora of reports on their al Qaeda connections. Please read his most recent report on them here. Please read his report on the UN recognizing these ties here for other links to just a small portion of his extensive writings on the group.
Pictures showing the checkpoint in western Benghazi can be seen below