I like the idea with what appears to be an old-fashioned desk and the watch and the child. Not so sure about cropping the top of his head off, and could probably have cropped off more of the bottom of the desk and a little off the left to get the watch on a rule of thirds line. JMO.
I like the tones. If I didn't know it was a time challenge, I might not be able to figure out what the object is in this cute kid's hands. No matter, the absorbed attention is well captured. It's simple, & I like it.