Note that I have observed that the "Gunner" position for the Hunter has a discrepancy for PiP, as at times it will provide the "live feed" to the computer monitor in front of the character, leaving a black screen on what is assumed to be the HUD eyepiece. Other times, it will black out the Hunter's computer monitor, and will display (what is supposed to be) the monitor's feed in the HUD window, or at times will simply show the "frame". The exact same behavior occurs when the player occupies the "Commander" position of the Strider as well.
Picture provided displaying an example of this behavior.