Below is how PM News reported it...
It was not possible to tell whether the footage was staged for propaganda purposes, especially scenes of residents cheering Islamist fighters. The message appeared to be aimed at reinforcing Shekau’s claim that he has created a caliphate within Nigeria.
In the 44-minute video, Boko Haram voices support for other so-called caliphates, including the one proclaimed in Iraq and Syria by the Islamic State (IS) group.