This Drone is controlled by someone on a tablet. It is marking some hostiles hidden that are hidden behind a billboard.

Companion Gaming is a revolutionary next-gen feature in Tom Clancy's The Division

Companion gaming allows a player to join the game from a tablet device using the Companion App, and help the other players by controlling a drone with a bird's eye view of the battlefield. The drone will have various support capabilities such as laser tagging the targets.

It is unknown whether or not the Companion App will support all devices or only specific ones

EDIT 06/23/2015 Companion Gaming has been canned http://www.eurogamer.net/articles/2015-06-23-the-divisions-companion-app-has-been-canned