We need a picture. Are they larger than, say Moshe’s Falafel, which has always been a 5-6 person setup?
Could be a NYC phenom, or just the newest thing in carts coming everywhere.
Some city things just can’t be explained to outsiders. Makes me think of when a a friend moved into town from Denver and we were stuck in traffic behind a rolling billboard. She asked, "what are these narrow trucks?" I said, "they’re billboards." "No, the trucks." That went on for about five minutes.