be aware that even though these stock agencies may refuse it, it is perfectly legal for you to sell your photo as stock photography.
when a submission is rejected, you can email them and ask why. they will almost always tell you why it was rejected, even though they will complain about it.
it is nice work. I saw similar work where someone took photos of miniatures, outdoors, with real trees in the distant background so the trees made the miniatures look full size.