I submitted about seven fireworks images, and most of them were rejected, I'm guessing, by some Adobe automated recognition system that simply stamped "Similar file already submitted." My guess is that the Adobe automated system does not see how one fireworks image can be different from another. Is there a moderator or a human decision maker I should write to to have him/her re-evaluate my images?
There are hundreds of thousands of fireworks images in the collection right now. To really be considered unique there should be a location or something unique to your image that separates it from others besides the color or specific pattern formed. Without seeing your 7 examples it's impossible to say exactly. I recommend you post them in the critique forum and ask for some specific feedback.
As for your comment about the automated recognition system...that doesn't exist. All content is reviewed by a human individually. No robot assistance involved.