The disc menu labels this as the technical commentary, and Lynch and Gainer certainly do not skimp on production details. You will learn about lighting choices and the models of HD cameras Gainer used, which had to be serviced by Sony after filming because of the dust ingested by their internal fans. They drop some non sequitur anecdotes about filming in Serbia, a broken Nespresso machine and hot dogs, but they mostly stay on point and offer an informative commentary. I had not realized that they only shot in one room. Lynch also speaks about the other films that influenced him and the directors from whom he drew inspiration. This commentary illustrates that much thought was put into what is not exactly a deep and pensive film.