I have reuploaded the JetBlue A321 photo at COU multiple times after addressing rejections due to incorrect contrast and exposure settings, along with addressing CCW rotation rejection and even with low-in-frame rejection. I have done all of the above and yet, the only reason why my recent upload of this particular photo was recently rejected is due to the aircraft "low-in-frame," and I don't believe it should be rejected.
Here are my two recent versions of the photo in particular:
It's a little low in frame for me by just looking at the thumbnail. I would try to aim to put the window like of this one on the middle weighted line. You actually might be better using a 16x9 ratio on this image to reduce the amount of the ground equipment cluttering the bottom of the frame.