"Same live picture" was the actual solution, not a description of the problem: the drone operator and the guard needed to see the same event, at the same time, so both could act on the same information. The command room also carries higher permissions than the guard - editing waypoints, gate positions, fences, and flight presets - so the same screen had to serve two different levels of control.
Sites with more than one drone add a second problem on top: a single command-room operator may need to watch and manage several drones at once, each with its own video feed and its own position on the map. The default single-drone view couldn't just stretch to cover that - it needed a dedicated view built for it.