Very clever and well done. I like the approach, but I would ahve liked to had more of a closeup with the girls face and turtle. It's almost secondary to the box to see the little guy in the spoon, but that's IMHO important to making this more than a fake product box shot.
Nice idea! Although when doing a mockup box, you might want to make sure that all sides of the box are done so that people don't know you just covered a box of Raisin Bran. And I don't know if that's a real baby turtle but aren't those are protected and not allowed near humans? Lighting is a bit bright on the model's face and background is a bit distracting.