Symmetry generally conveys two primary meanings. The first is an imprecise sense of harmonious or aesthetically pleasing proportionality and balance; such that it reflects beauty or perfection. The second meaning is a precise and well-defined concept of balance or "patterned self-similarity" that can be demonstrated or proved according to the rules of a formal system: by geometry, through physics or otherwise.
Because this thread was about King of bodybuilding symmetry, this aspect needs to be considered.
Bob Paris has to get a mention. He was still competing on the Mr O stage and holding his own against much bigger guys.
The only problem with posting his pics is that most of the google results seem to be from gay blogs.