I like the idea. The kid and the sign balance well.
I'm wondering how it would look with the camera more level and less sky. Could be better (straighter vertical lines, more interest from the carnival surroundings), or could be worse (too many distracting elements, too busy).
This is the kind of situations that you don't have much time to frame, or compose, but it is relatively easy with a XPan, you just have to watch over the perspective. I don't know if you made more than one shot, as David suggest, could be interesting to see them.
For me, this photo is great, and is great because the framing, you can appreciate with no doubts that it is a country fair, but you give all the importance to the kid and the sign that suggest a name. Reminds me Mary Ellen Mark's kind of portrait.