What happens when two images are considered not alongside one another but as backed by each other? The spatial dimension of comparison—long cherished and recently challenged by technologies that enable the study of the history of art—would no longer be established according to the direction of reading, as sinister versus dexter, gauche versus droit. Gone would be a linear trajectory of progression that sequences an established mode of pictorialization followed by a dissenting response. Instead, this new arrangement might indicate a relationship of support—something or someone behind something or someone else. Or it might inflect the represented element with a temporal suggestiveness that is murkier, less direct in causality than the side-by-side placement, as if something were lurking in its past. Two images on either side of a single sheet can never be face-to-face. And because they cannot confront each other, they are an affront to each other. They do not afford one another enough space. The writing of art history would be less a teleology, less what Heinrich Wölfflin describes as “an objective pull of movement from left to right,” than a ghost story—an attempt to facilitate communication between one image and another that lingers as an apparition in rear view, faint but attached.