An accomplished painter, whose watercolors grace the covers of some of her books, Elizabeth Bishop is very much the pictorial poet. "Oh, but it is dirty!" the opening exclamation presents the picture of a grease and "oil-permeated" gas station that appears to display not only carelessness, but neglect--"Be careful with that match!"
That the owner and his sons are equally as slovenly is indicated by father's "dirty oil-soaked monkey suit" and the son's greasy clothing. Appalled by all this oil and grease, the speaker wonders if they live at this station as she notices
a set of crushed and grease-
on the wicker sofa
a dirty dog, quite comfy.
and wonders at the feminine touch in amid all this grime: "Why, oh why, the doily?" But, it is at this point that the speaker comes to realize that, albeit "oil-soaked," the filling station has the makings of a home. For, beneath the grime, there is evidence of unity as the sons have probably fingered through the comic books while sitting on the "impregnated wickerwork" as a dog--himself covered in grease as one of the family--lies contentedly upon the wicker sofa.
The "hirsuite begonia" suggests a love of beauty amid the toils of the men at the station, Further, "somebody"; namely, the wife and mother, tends to this hairy plant, connotative of the men, and lays a doily lovingly under her sons' comic books. These pivotal details project the speaker into the realization that "Somebody loves us all" and even in greasy filling stations there can be loving relationships.