In the current state the live feed module has plenty of potential, but seems under-developed.
Specifying a target should only seem necessary in very niche cases, as many times one simply wants to invoke Live Feed PiP to see what another NPC "sees". Instead if a target is not specified, the camera feed seems to use the player as a "default" target.
If this was changed to allow the default target as whatever was in the "source" NPC's field of view (eg: First Person NPC "helmetcam" in lieu of the floating camera), immersion would be enhanced greatly.