Actually I submitted a bunch of these to Lightstock, and I was surprised that some, like this one, weren’t accepted. I wasn’t quite sure why.
Quick update: I found out why! I had trouble uploading a bunch of my photos, and many of them had failed to upload. 🙂 So I just have to retry that. Also, I figured out where I can see which photos they rejected and where they say the reason they rejected them.