Yet for all the pomp and glory, there is perhaps a touch of irony in Piranesi's visual emphasis on decay. The structure is imbued with both physical and metaphorical ruin. The scars and wounds of the facade in the exposed brick and stone, are made visible by Piranesi's forceful and jagged incisions onto the metal plate. The glory of conquest, retained only in the well preserved bas relief, is on the verge of destruction, surrounded by the crumbling, overgrown, and broken pieces of the architrave, central volute, and heavy fluted columns, of which only the base lower shaft is still standing. Lowly activities by the actors in the foreground now amalgamate as the outcropping of medieval and Renaissance buildings pile on top of one another in disorderly succession. A "veritable anthology of deterioration" is how art historian John-Wilton Ely has described the scene (1978, 37).
Decay is additionally underlined in the text between the words "spoglie" and "spogliato." Piranesi contrasts the "spoglie [spoils]" brought back from the war depicted in the reliefs, and the current state of the Arch as "spogliato [bespoiled, divested]," having been stripped of its decoration and ornament in later periods. The prominence of the gothic looking tree provides a foil to the Arch, further highlighting its ruinous state (Wilton-Ely 1978, 37). The jagged lines of the trees and branches are reproduced in the plant-like veins of the exposed and rough stone. What is produced by nature and by art is deliberately blurred through Piranesi's juxtaposition of light and dark, as well as different textures, almost as though man-made structures have become fused with their natural environment.
To see this image in Vedute di Roma, vol 17 of Piranesi's Opere, click here.