It is cobbled together footage from other sources. They made a glitch in video editing that gives it away. They make the video cut just a second to late, and it gives you a brief gimps of the next video clip on the source they was taking it from. At 1.33, you see a quick glimpse of a building right when it explodes from a missile strike.
The sentinel drone does not carry weapons.
It is operational footage from armed drone missions.