Many of the iconic timepieces throughout history have been known for a certain look, most likely centering on dial aesthetics. Exhibition case backs have gained in popularity, as watch designers work to give collectors a view of the mastery of the inner-workings of the engine driving the timepiece. And with that, rotor designs have become more ornate, adding yet another reason to fall in love with an automatic mechanical timepiece.
Watch manufacturers quickly learned, there is only so much information that will fit onto an automatic watch rotor, and only so many modifications that can be performed on a rotor and / or movement, and maintain full functionality and accuracy of the movement.
Enter the case-back. The case-back has become the official canvas for watch designers to express certain details, many intricate, about the timepiece. And you can certainly enter much more information on a blank case-back, than a rotor, which is more than 1/2 the size. The case-back detail in some timepieces is so amazing, it becomes the major driving point in a collector's decision to purchase the timepiece; case back detail on the Omega Seamaster, Zodiac Oceanaire, and Zenith, Montre D'Aeronef immediately comes to mind.
So while you may be enamored with the dial, bezel, case, or strap of your latest watch purchase, be sure to check the rear of the case also, because there might be a party going on around the back