It kinda looks like he's an old NRA style .22 pistol shooter shooting a postal match. He's been watching Olympic shooting.
Not sure. When I was young I was taught to shoot that way. I was not quite into my teens (12 I think) and he was in his 90s. Supposedly a retired Texas Ranger according to everyone that knew him and some old photos in his home. He told me, you shoot one handed and turn side on to the person you are shooting at. He said and I quote "Most bad guys can not shoot for shi+ so you are giving them a smaller target." I still can not get comfortable shooting any other way. I know there are better stances but I can not break the habit.