Agent Cooper rocks that calm, sincere constant self-detailing dialog again and again. He is so self-referential. He is constantly pointing his finger at himself, to say, see me, I am different, I see every detail, I really appreciate the coffee, the doughnuts, and I don't just shove them down my throat, as we witness Deputy Andy does as he gulps down his doughnut!
(I thought he'd choke on it! The cliched cops and doughnut obsession is done with great humor also with the table laid out with so many piles of doughnuts. The day after 9/11 I bribed my way through a police blockade by offering the officer some of my homemade doughnuts, no I'm not kidding.)
This talking into the tape recorder is a device that is a constant reminder that Agent Dale Cooper has to justify his own shadow, as a city guy in the woods, in a town where he already stands out dressed in his fine suit, and his every move is watched, by the townspeople, the FBI, and us, the viewers.