The Perspective of Surveillance Equipment
From the start, the film uses clever photographic tricks to give the impression of looking at the scene as if through optical surveillance devices. We see Union Square through the crosshairs of a telescope. Ann and Mark appear in the square, and the viewer catches glimpses of them over the shoulders and between the bodies of foregrounded pedestrians. These photographic techniques give the impression that the audience itself is spying on the young couple, and puts us in the mental perspective of Harry Caul and his associates. The camera turns into a spy, and into a surveillance device, which immerses the audience in the drama and suspense of the plot.
David Shire's Soundtrack
The soundtrack is very influential to the viewers' perceptions of the events in the plot. While some of the diegetic music can be upbeat and straightforward, David Shire's score is consistently eerie, unnerving, and suspenseful. Dissonant chords create a sinister tone, as though danger is lurking behind every corner. While so much of the film is left vague and mysterious, the score accentuates the fact that there are more grisly and disturbing events to come. In The Conversation, if one peels back the surface too much, one is sure to find some unsavory evidence, and the uncanny piano score perfectly portrays this.
Open spaces
Open spaces abound in the film. First, we are dropped down in Union Square, a crowded and motley public forum in which Harry Caul is conducting his surveillance work. The public square is seemingly anonymous—Ann and Mark feel as though they are safe to meet and talk there—but little do they know they are being watched. The open square is busy, but this makes them more vulnerable.
Another important open space in the film is the warehouse which houses Harry's workshop. The office itself is nestled in the corner of the warehouse, but most of the floor plan is just open space with columns dividing different sections. The warehouse is even big enough for Stan to drive a motorcycle through it. Just as Ann and Mark thought they were protected when they walked through the open square, Harry feels safe enough to confide in Meredith, when they walk around in the open part of the warehouse. They are being watched, however.
In addition to these two spaces, Harry's home and the office building where Harry brings the tapes and photographs are both notably open spaces. There is hardly any clutter in either. Harry's apartment seems to only be a place to sleep, and there are no extra adornments anywhere; furniture and decoration are strictly utilitarian. In the director's office, long hallways echo with the footsteps of visitors, and large windows frame expansive views of the entire city. The starkness and openness of the office represent how powerful and imposing the corporation is.
Bloody Toilet
Perhaps the most evocative, disturbing, and supernatural image in the entire film is the bloody toilet that Harry comes across in the bathroom in room 773. The entire scene is somewhat surreal; even though Harry saw a bloody handprint on the divider between the balconies of the two adjoining rooms, he finds the room itself completely clean and pristine, as though no one has been there. This suggests that there is some kind of a disconnect between Harry's perception and the reality of the situation. While everything seems extremely clean, when he flushes the toilet, it immediately fills with blood, which overflows the toilet, and flows over the edge of the bowl. Because the film maintains a realistic visual palette throughout, this image stands out because it is so surrealistic and supernatural. In this way, the blood becomes an emotionally evocative image, a dream-like vision, representing the terror Harry feels at having been so close to a grisly murder.
