I think the Grateful Dead Movie really does a great job of conveying many of the facets of the Grateful Dead concert experience, which was Jerry's goal with it. From the deadheads of all shapes and sizes, to the exasperated cop dealing with the "getting my space together" guy, to the shamelessly ogling food vendor, to the crew setting up the equipment, to the guys sweeping up at the end.
The last time I watched the movie, however, was the first time I noticed that Jerry could have been also trying to convey what it is like to be a member of the band. There is a point where the footage cuts to Phil, soaked with sweat, locked deep in the throes of a hot Playin' jam, with the band working their way toward the reprise.
The angle is sort of from behind the neck of his bass, which first gave me this idea that, maybe this is kind of how it would feel on stage. As they get to the repeating figure, which precedes the reprise, the footage cuts to Jerry, playing that repeating figure over and over, bringing the volume lower and lower, with him mouthing "shhh" to the band, masterfully bringing the dynamics down to a pin drop, and upon reaching the "turn around", bringing them back up, to full volume at the point of release, when the band slams back into the reprise.
I think Jerry was trying to let us know how it feels from the stage. Just something I noticed on my last viewing of the Movie, check it out next time you watch it š