Imagine being totally surrounded by sound and visuals, having your electronics (or the IFE) plugged in, or simply decide to dim everything around you. A inflatable cushion adds to the comfort (and acts as a kind of airbag during turbulences).
The headrest here offers the passenger the possibility of choosing one of the other of the types of ambient [oxygen] flow, refreshed or conditioned. The distributed air can be enhanced with or more natural or synthetic odorous substances.
Airbus is going into virtual reality territory. You forget you're in a plane—or at least that's kind of the intent here.