With the newly revised Classic rear, it looks like the changes were made in the camera lense area. If you look closely, it almost looks like a larger opening for the lense, and possibly a larger LED that is pressed closer to the lense itself. The old revision of the Classic that Chen brought out at a few months ago looked like it had essentially the Q10 setup.
Attachment 296537
I wonder if they're using the same 13 MP Camera With OIS camera that the Passport has. Judging by some new photos taken on Weibo, the Classic looks like an improvement over the Q10. But there could be other factors in play too, like software updates and this could all just be an aesthetic change to the exterior. Hopefully we hear something official soon.
Attachment 296536
Classic
Attachment 296535
Q10