This makes it easier to see. I copied a square out of the Kindle 2's blank area (above the tree) and pasted it into the iRex and Cybook. There has been no adjustment to the photo since I took it except for size reduction (and cropping down to the three devices in this view).
Edit to add: Let me repeat that it may be possible that there is variation in the quality of output when these screens are made. I may have gotten an exceptionally good one with the Cybook and an exceptionally bad one with the Kindle 2. The only way to know is to compare with others and I only have these.