While flying back home from Boston, I was reading a book that described a panic attack and I came to the realization that the last scene of the Sopranos was all about making the audience experience a panic attack. There was a scene that would have been normal for any family in the United States, but many seemingly small details of the scene caused anxiety for the viewer. It all started with Tony coming into the room and checking everyone out. The camera flits back and forth like you had darting eyes. He sits facing the door, looking up quickly as people come in. Another person walks in and Tony darts his hand into his pants, only to pull out change for the jukebox.
After Carmela comes in the camera still wanders around the room, seemingly assessing people for their potential threat. It lingers on suspicious people. A man walks in in front of AJ, and the camera lingers on him, too, until AJ starts to sit down. We see the guy sitting at the counter who seems suspicious, and AJ seems to be nervous. We observe in excruciating detail Meadow's seemingly careless and clumsy parking and crossing the street. The camera linger son the car like we're expecting an accident.
The man at the counter walks past and goes to the bathroom. Tony looks at him and assesses. AJ acts nervous. Two more guys wander in and seem to loiter. We hear a car long before it passes safely behind Meadow as she runs into the restaurant.
And then there's sudden silence after Tony looks up, with a look more like surprise than recognition of his daughter.
What I'm trying to say is that the scene fills with growing tension before the sudden blackout, just like an unexplained anxiety before a panic attack and blackout. I think David Chase wanted the audience to have an panic attack like Tony experienced several times during the series. I'm not sure if he was trying to give people a glimpse of how Tony felt every day at the beginning of the series, or just pointing out that's what his life is like all the time. After all, we had quite the vicarious thrill following him up to that point.