Nice piece. Surprised that the main instrument isn't the cello, given the image!
I really like the minimalism; the music box (glockenspiel?) sounds great. The string VSTs are a little weak (or maybe it's because of an effect you added?), which is more noticeable when there are few instruments.
You have a single motif, which works well. But after a minute of music, it might be nice to add a melodic variation (other than repeating the motif with a different instrument) or a contrasting theme. Ryan Leach made a pretty good video on the subject, I could find it for you if you want.