Rejected "contest submission" for "hint of audible room echo"

Reposting here after initially posting in "feedback" as well.

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Just submitted my first "contest" and got a revision request (then before I could adjust things: a rejection) for  "a hint of audible room echo (reverberation caused by recording space.)" 

I've long ago had my room tested and produced quite a few pieces in this space including my "application project" which went through the first time without revision request. I've re-listened to this sample multiple times and still can't hear the issue described.

I appreciate the feedback from anyone with some good ears to tell me I'm missing something.  I'll put my account on hold and rebuild my recording booth or treat as needed. As of now there is acoustic treatment on all walls and ceilings and this is a 4x5x7' space. I do not have a "reflection filter" because it seemed that I had more than enough sound absorption behind the microphone, however I will make/buy one if the consensus is that I DO have audible reverberation.

Thanks!

File in question:

https://www.dropbox.com/s/0aoznuwllwb9d4a/OneMillionLoops.wav?dl=0