It's pretty easy to tell what's going on with AI Angel Angelica. If you've watched some of the videos, you'll notice the steady progression of the real-time rendering. The first videos were really jittery and there were a lot of movements (awkward mouth movements, fingers unable to move, etc) to the more recent ones with realistic-ish mouth movements and full finger movements. So, they started off with a motion capture program with a special suit to capture movement. As they progressed, the suit got a lot more sensors and the programming itself was streamlined. As far as it being artificial intelligence, no, it's not. There's a person in a suit talking to a camera that's been programmed to pick up movement and translate it onto an avatar. Based on the movements from the most recent video, there are sensors on a few parts of the face, neck, shoulders, elbows, waist, hips, knees and feet and probably 3 on each finger, 2 on each thumb. Based upon the camera movements the programming is designed to follow the avatar, which is why it seems to follow her when she moves around and additionally, she's able to turn around while the camera remains in place. There is probably a face camera attached to the suit to track the minute facial changes (think of the movie Avatar) and two or three cameras mounted around the area to pick up the rest of the sensors (which could just be colored dots).
The setup is probably a greenroom with furniture in some of the places the furniture shows up in the 3d 'room' she's in. There is probably another camera or sensor that is used so she can move around when she shows off her computer setup. The model probably just uses a button to switch between them. I don't know if the voice is real or altered, but it has changed over the course of the videos. If it is real, the model is probably female speaking in real-time. Whether or not the model is also the developer is another question. I don't know.
Regardless, the real-time rendering and advanced 3d space analysis requires a pretty hefty computer setup, so whoever is doing this is on the level of a professional with professional-grade computing power. It is WAY beyond anything I'm capable of at the moment, so my hat's absolutely off to the developer and/or model. Extremely impressive.