I'm not sure what this comment is supposed to add. Maybe to say that you don't need to resolve an image very well to detect a face?
In any event, the resolution of your imaging system is fundamentally limited by it's aperture. That is a limitation dictated by physics. You can play fun games with synthetic aperture provided that you can recover the phase of the incoming radiation, but recovering the phase of 700nm radiation is really hard to do. There seems to be a misconception that a single-pixel detection system is somehow immune to diffraction, but this is simply not the case.
In any event, the resolution of your imaging system is fundamentally limited by it's aperture. That is a limitation dictated by physics. You can play fun games with synthetic aperture provided that you can recover the phase of the incoming radiation, but recovering the phase of 700nm radiation is really hard to do. There seems to be a misconception that a single-pixel detection system is somehow immune to diffraction, but this is simply not the case.