One of O'Sullivan's most powerful photographs, and most likely his best known, is just such a trace of destruction. It is revealing of O'Sullivan's technique, and representative of the individual strength of his photographs. As we have seen, "A Harvest of Death", in the context of Gardner's Sketchbook, can make a political statement in which the "distorted"5 corpses become signs of the evil of the Confederacy. However, we sense that the photograph holds another meaning. For, the floridity of Gardner's caption only accentuates the fact that it is excessive not only in and of itself, but in relation to the photograph that is so powerful, it needs no caption to speak for it.

Much of the power of the piece comes from O'Sullivan's use of formal elements such as detail, composition, repetition, and focus which lead the eye into and through the photograph in a direct confrontation with and thoughtful contemplation of death. O'Sullivan gets his viewer to scrutinize the details of the photograph but also causes his viewer's eyes to keep moving throughout the composition. This maximizes the visual power, dramatic effect, and range of response from the viewer.

O'Sullivan elicits the careful and attentive look of his viewer through the use of detail and composition. In looking at the photograph, one's eye is immediately drawn to and absorbed in scrutinizing the corpse in the center and at the bottom of the image. This is because it is close enough to be viewed with some detail and the detail it offers is particularly captivating. This body is the only one whose face can be seen, and the face is the most identifiable and captivating feature of a person, and certainly of these uniformed and anonymous dead. The most compelling part of the photograph is the corpse's open mouth and bloated lips. They almost appear to be abstract shapes. The lips outline the circular shape of the open mouth, and emphasize the darkness of the orifice by way of its contrasting lightness. The thick, light lips are themselves emphasized by the darkness of mustache and beard around them. The mouth is captivating not only because of its outlined and circular shape and contrasting values, but because of its distortion. Wide open and bloated, it entices the viewer's perverse curiosity. In fact, the bodies immediately above and to the right of this one are in better focus, but the mouth of the first makes it the focal point. The bloated hand also excites perverse curiosity and draws attention.

O'Sullivan's use of focus and composition also make this figure the focal point. Foreground and background are both blurred, leaving only a small portion in the middle of the scene in focus. This is approximately the area where the central body lays. Because we fix our attention on what is clear and detailed, the focus forces the viewer's attention to this central corpse as well. Finally, this body is the focal point because of its location in the center of the composition, horizontally, and in the front of a row of receding bodies.

The receding forms create the depth and movement of the photograph which keep the eye moving throughout the composition. They draw the eye into the picture to the corpse in the center and then further into the depth of the scene to the rest of the figures, up to the horizon and empty sky. The horizontal line of the horizon then draws the eye across the photograph to its edges and back down again to the bodies on either side of the centrally located corpse. Once in the foreground again, the eye is drawn once more to this corpse. The power of the photograph comes from the tension between the movement created by the receding line of bodies and the power of the central corpse to gain and maintain fixed attention because of its detail and location. This tension is also created and epitomized by the mouth, which repels the viewer even as it attracts him.

The movement the composition forces upon the eye, forces the viewer to engage with the subjects of death, violence, and war. The viewer is drawn into the pictorial space, onto the battlefield, by the receding line of bodies and her imagination and empathy are engaged. The detail and placement of the central body puts the reality of death right in the viewer's way. She realizes that, in an open field in Pennsylvania, the distorted, almost abstracted bodies are the evidence not of an abstract force, but of human violence.