They say eyes are the windows to the soul. At the very least, eye contact is one of the most intimate forms of connection two people can make with their underwear on. Valve spent a fortune ensuring that looking into Alyx Vance's eyes wouldn't be robotic and awkward. A big reason for Vampire: Bloodlines' characters being so successful is that they, likewise, hook you in the eyes and refuse to let go. Of course, being a horror game, some of them would probably rather be doing it with a fish-hook.
In virtual reality, eye-contact becomes code for 'alive'.
It doesn't matter if the person is FMV or CG or even an active participant. My favourite VR demo, Arkham VR*, demonstrates things better than most, whether it's Joe Chill's gaze following you around Crime Alley or standing face to face with Batman characters in his little holographic simulator. Even if a character can't actually do much, it's ridiculous how effective simply a small head turn, a blink, or tracking your own eyes as you walk around can be. It's a level of intimacy - no snickering, please, I'm not talking about the many purveyors of VR porn out there - that you just don't get with a conventional monitor in front of your face, as well as one of the many frustrating parts of the VR experience that can be described, but really have to be experienced to 'get'.
(* Virtual Rickality, above, is fun, and had better screenshots. So why talk Arkham VR? Sadly, Rickality shoots itself in the plumbus by limiting Rick and Morty's presence and being mostly about standing alone in a garage, with Rick on speed-dial. Grr. As if anyone wanted Not Rick And Morty. With the possible exception of non-Rick and Morty fans. But why would they buy one of their VR games? No, sir, it makes no sense!)