Sublime camerawork

Agreed. The cinematography was excellent, especially in the final scene.

That's a very interesting and insightful way of putting it. The camera moves as if operated by someone indifferent to human behavior -- so we don't just get alienating extreme wide shots a la Kubrick, but strange pans over to seemingly irrelevant things (cars passing, a hotel painting, the aforementioned wire on the wall, ceiling fan, etc.) I haven't seen another film quite like this. Even Antonioni's other films have a much more rigid, locked-down quality to the cinematography, which tends to frame characters in alienating surroundings rather than abandon them altogether (although the incredible ending of L'eclisse does precisely this).

An interesting thing about the perspective in this film is that although David Locke (Nicholson) is the ostensible "star" or "protagonist" of the film, his absolute passivity and refusal to commit to anything can be seen as one of the reasons the camera seems to wander back and forth to seemingly unrelated subjects, as if to say that Locke is such a complete non-entity, even in his own life and story, that the camera does not remain focused on him in many of the scenes that he's in. A truly brilliant film.