Nighthawks was probably Hopper's most ambitious essay in capturing the night-time effects of manmade light. For one thing, the diner's plate-glass windows cause far more light to spill out onto the sidewalk and the brownstones on the far side of the street than is true in any of his other paintings. As well, this interior light comes from more than a single lightbulb, with the result that multiple shadows are cast, and some spots are brighter than others as a consequence of being lit from more than one angle. Across the street, the line of shadow caused by the upper edge of the diner window is clearly visible towards the top of the painting. These windows, and the ones below them as well, are partly lit by an unseen streetlight, which projects its own mix of light and shadow. As a final note, the bright interior light causes some of the surfaces within the diner to be reflective. This is clearest in the case of the right-hand edge of the rear window, which reflects a vertical yellow band of interior wall, but fainter reflections can also be made out, in the counter-top, of three of the diner's occupants. None of these reflections would be visible in daylight.