I know too little about film or production to say much about this, either, but: the film used a lot of shot-techniques or whatever that I recognize from promos for films and reality TV shows. Here is the staff of the restaurant, arranged just so, staring into the camera; it is slightly slow-mo, the camera slightly pans to give dimensionality, but nothing is really happening. This is how you make ads and music videos, not documentaries, which ought to have something to impart beyond “tune in!” or “this! this! this!”
A documentary about an artist which fails to even discuss what is unique about him or his work, how he works, what he is good an bad at, with what he struggles, what the nature of his excellence is: such a documentary must be a failure.