KH1: Kosher Howie is Jewish, and proud of it, all over Jersey City

It's a bit difficult to make out, but over to the right of the dreidle, just above his tag, KH1 has noted: "I'm a Jewish Toy." That's a pun. A dreidle, of course, is a Jewish toy. But "toy" is also graffiti slang for an unskilled writer, possibly one new to the craft.