The lighting and composition work well. The object on the right hand side that is reflected in the surface detracts from the impact of your composition though. I would suggest that a dark matt surface would really enhance the colour of the truck and contrast well with the rice.
The photo itself isn't bad. Maybe a little dark on the right side and the reflection detracts from the image. I am having trouble figuring out how the rice shows that the fire truck is miniature by comparison.
Nice idea of "cargo" to show scale but loses out because of poor background. The background is dirty and really shows reflections that have nothing to do with your image. This idea needs further development to make it more striking - what about non-plain backgrounds? 6