Like anything else, Golf Club Head Design is directly related to customer acceptance which can be determined by functionality or looks. This is why some companies start with what they think will have the highest performance and then design the graphics of the head around that premise. In this case they are thinking function first and appearance second. For instance Mizuno tends to focus their iron design on functionality first, and once they get a head that performs well and has the right characteristics to assist the golfer, they then figure out a way to make it look appealing.
Some other companies tend to structure their equipment design around graphics first and then function later. There are companies who place a lot of emphasis on how the design, graphics, adjustment options look, rather than what they actually do to help the golfer. Of course, they do blend in performance at some stage, but that is not their primary focus.
Form versus function in golf club design has perplexed designers, engineers and marketers for decades in a three way tug of war which will ultimately be determined by what the public wants. This article focuses on the functionality and engineering concepts which make up a good golf club, as in my opinion these are the most important elements in the design of a golf club that will contribute to improving your golf in the long term.