One of the most obvious differences between the rep and the gen is the CG but not face on but profile.
Face on, on the wrist they are almost identical.
Left gen, right rep
Up gen, down rep
Another thing though that NONE has ever mentioned is the thickness of the caseback..
Gen caseback is THICKER than the rep one and it IS visually obvious when you see the watches side by side and most important when you wear them because gen sits higher on your wrist.
I don't know if you will manage to see from those photos but in reality it is considerably more thick.
rep: