I don't think you understand what I'm saying. I'm not talking about using the keyboard, just about having the keyboard other half on. While on N900, you have the camera on the back side of the keyboard, on Jolla it is (if such thing as keyboard exists) in between the keyboard and the screen.

To be more illustrative:
grab your N900 in portrait mode and imagine the screen is Jolla and the keyboard (the actual device) is the other half and you have the camera placed on the front part. With keyboard closed, there's no way you could take pictures.
Now open the keyboard - you would be able to take pictures if the camera was on the right side, but guess what... Jolla has it on the left.