Happy to relay an explanation:
"A while ago we have experienced problems with some photos uploaded from iPhone/iPad not being rotated correctly. To remedy this, functionality was added in the uploader that reads EXIF data of the images in order to properly rotate them when needed. This functionality has been working just fine but is in itself relying on an external Exif library module. It would seem that after our recent move to the new server, we have received a different version of the library.
EXIF data is the additonal textual data saved in the image file that is designed to hold information on the type of camera used, lens/aperture settings, location of the photo, orientation etc. It is supposed to be standard but its practical use is notoriously "dirty", typically being populated to rather liberal standards by all kinds of devices and programs that take, edit, resize and even copy your photos. What happened here is that due to whatever discrepancy our Exif function could not properly read picture orientation values from some of your images (not that there was necessarily something wrong with the pictures themselves - it might be a bug in the Exif library or junk/unexpected data in the corresponding Exif fields). This error has been causing the upload process to fail uncontrollably with "Error: error" as a visible result.
A simple improvement in EXIF error handling (one line of code) remedied the problem. "
Pardon the lenghty explanation, but this could perhaps give some insight into how we're working - it's getting a bit technical sometimes 🙂
/m