I see from the EXIF data the camera and flash were in an automatic mode and your metering was set to Matrix. The camera selected an ISO of 720, 1/125, and f/4 and the flashwas in auto mode too. Your lens was zoomed to 26mm and the WB was on auto, and you ran the photo through the free software, Picasa 3.0.
Did you know the flash was going to fire?
Do you take all your photos as JPEGs, rather than shooting them as RAW data files?
The boy's expression and position is sweet, save the cut-off arm.
The background is kind of busy and bright. Knowing how to use strobed light (flash), the background could have been rendered darker so the boy was more the center of attention (light advances, dark recedes).
It's to bad you missed the focus on his eyes, but the D90 only has it's single, cross-type focus point right in the middle, so it would have had some difficulty focusing accurately in hard shade.