personally, i think it's a subconscious homage to Godard (especially G's final cut reverie re: nature vs. the contrivances of human social networks), particularly the film he references intertexually throughout Mulholland Drive, Jean-Luc Godard's Le Mépris (Contempt).
re: the previous post, David Lynch insists, "It's absurd if a filmmaker needs to say what a film means in words" (19). absurd? yes. part of the game? also, somewhat regrettably, yes.
also, in a chapter entitled "The Box and the Key," Lynch reveals, "I don't have a clue what those are" (115). ha!