Mar 4 2015
I reproduced it reliably, multiple times, both from scratch and by clicking the 'Retry the failed uploads'.
Feb 22 2015
FYI, I just got the same error with a different set of 5 JPEGs
Feb 21 2015
UTC+1. Just pressed the 'Retry failed uploads now'. Thanks.
OK, thanks for looking into this. In my case the actual upload goes OK, then I get the upload error described above when I try to finalize the 'Describe' step, see attached screenshot.
Feb 20 2015
The first two attempts (using JPEG): ca. 9 MB each
The third attempt (using PNG): ca. 41 MB each