It’s a sign.
This is clever art. Think of it. Think of the idea formulating in the back of the artist’s mind. Think of the him planning a perfectly-cast shadow. Think of him etching in the letters “W-A-R” in the same font and height as the word “STOP.” There’s just something intriguing about the process of creating this. And a note of jealousy too—like wishing you’d been the one to think of it.
Some degree of respect deserves to be awarded to this graffiti artist. Rather than haphazardly scribbling “war” on the stop sign, an act which most assuredly would be considered common vandalism, he created a piece of art.
In effect, more than a sign.