Bradcalkins is absolutely right... the batch of images you submitted was reviewed from different editors and every editor only saw some images and not all of this series; best way to prevent getting not the best images accepted is only uploading the best images of a series...
I think it's best to always upload your best shots first, that way they won't be rejected because there are too many of the same subject. It's in your own interest to be very selective, as uploading very similar images will only dilute your revenue, no allowing you to reach Level 2 or Level 3 sales.
Nice pics. I too have encountered such type of problem, and my solution to the problem is don't upload all the pics in one time regroup them and upload at different intervals, chose best ones to upload and crop them to make some more interesting compositions from the repeating pics.
If you want them to select the best ones, you should submit just the best ones. On Dreamstime you see higher dollar sales with fewer images on a topic. I suspect the editors pick what they think is the best of the lot, but since they are submitted as individual images there is no guarantee they all go to the same editor for review at the same time. By submitting them all you risk getting some approved that aren't the best ones, and then having the "best" rejected since you already have some online.
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