Camera drone
From Halopedia, the Halo wiki
A Camera Drone (unoffical name) is a type of recording device used by Humans. It is probably used for playback on civilian-owned video displays as entertainment or acknowledgement on current events. The Camera Drone resembles a Forerunner Sentinel.
Apperances
You can only see this device once in the game. It is shown in the Halo 2 Cinematic Cutscene Home Field Advantage which takes place on Cairo Station.