You caught this boy at exactly the right moment. Kids have so much fun at fairs and amusement parks and your image, positioning the boy between these two "things", clearly communicates his joy.
Beautifully layered image, Tim. The reflected light on the child is delightful, as is the incongruity from layer to layer. The scale of the grins varies enormously -- the smiling kid is squeezed between the massive fangs front and back yet does not seem to mind being trapped between them.