Ed Ruscha Standard Station, 1966.
For those in a Lacanian frame of mind, the hoses could be read as instances of the Phallus, signifier of masculine agency within the context of the modern domestic sex-gender system--all the more appropriate given the deep cultural linkages between automotive travel, corporate industrial might, and fantasies of American masculine mastery.
This reading intuitively strikes me a quite promising, and it would be interesting to know what Ruscha himself would think of it. (In interviews, he has noted that the widely interpreted association of the sign "Standard" with the normativeness of dominant American culture is not one he had been consciously aware of while creating these works, although he is open to that line of interpretation.)
I am tempted to speculate that there might even be an implicit linkage within this image (and the many variations on the theme Ruscha has created) between biological reproduction and the reproductive capacities of the commodity sign in a capitalist context. Here we may have a protoypical modern, "standardized" family in which the parents have reproduced themselves in the form of their children, at several different symbolic levels. Each of the pumps, after all, sports the name and image of "Chevron" the most famous product of the Standard Oil Company. Under the modern schema of commodity aesthetics it is in the nature of one brand to beget another, ultimately subsuming all human experience under the arch-signifier of the endlesely-fecund commodity fetish. Thus, direct representations of human bodies would be superfluous in such an image: the logic of reproduction under modern capitalist conditions is entirely enframed with the capacity of the brand emblem ("Standard", which appropriately spans the scene) to spawn subsequent iterations of itself under subordinate brand emblems ("Chevron"); hence, we have before us the perfect family under modern capitalism, waiting, as it were, to glimpsed, and desired, by other families speeding along down the very highway made possible by the petrochemical industry.