I don't remember the details of that scene, but I don't think I ever considered it hypnotism. It seemed that it was just his "powers" in general, or partially the force of his personality, that he was able to command her and eventually get her to respond.
As Josete said, I think it was one of his powers, probably related to the hypnotism ability, but not involving direct eye contact. The vampire's will is overpowering.
Actually, vampires are often depicted exerting their will over people they haven't bitten. How many times have we seen a scene in which the person guarding the vampire victim falls asleep on the job because the vampire, who's somewhere outside and staring at the room, willed them to do so? And in those depictions it is quite often the case that the vampire had little or no connection at all to the person they're influencing, so I don't think relationships play much of a part in it. (Mel Brooks even poked hilarious fun at such scenes in his spoof Dracula: Dead and Loving It.)
Actually, vampires are often depicted exerting their will over people they haven't bitten.
(Mel Brooks even poked hilarious fun at such scenes in his spoof Dracula: Dead and Loving It.)