I'm sorry, I'm not seeing it.
First of all, that is an ebay listing, are any of us here 100% certain that is even an authentic bag?
The bag on the left is obviously slightly tilted backwards as it is on a stand of some sort. The rep posted is sitting on a soft-looking duvet which is causing it to sink into the bed and look like there is less space between the bottom of the bag and the flap when the turnlock closure is. The bag on the left is most likely stuffed for photography purposes. I don't know if the bag on the right is. The bag on the right appears that the two rings where the strap goes through is closer to the front of the bag than on the bag pictured on the left of the screen. Again, I think this is due to the positioning in the photograph. From the back I see no difference other than the fact that one or both bags may or may not be stuffed to encourage a better aesthetic. The pocket placement is the same, the number of "diamond" stitches is the same both vertically and horizontally, both sides.
I know I've said this before, but I just see a gorgeous bag on someone. Fake or not. Would I have the cojones to walk into Chanel with it? Probably not, but again, my concern generally is not with other people's bags, I'm too busy checking out how freakin' hot I am in the store windows!