This rendering of the Vitruvian Man, completed in 1490, is fundamentally different than others in two ways: The circle and square image overlaid on top of each other to form one image. A key adjustment was made that others had not done and thus were forced to make disproportionate appendages:
“Leonardo’s famous drawings of the Vitruvian proportions of a man’s body first standing inscribed in a square and then with feet and arms outspread inscribed in a circle provides an excellent early example of the way in which his studies of proportion fuse artistic and scientific objectives. It is Leonardo, not Vitruvius, who points out that ‘If you open the legs so as to reduce the stature by one-fourteenth and open and raise your arms so that your middle fingers touch the line through the top of the head, know that the centre of the extremities of the outspread limbs will be the umbilicus, and the space between the legs will make and equilateral triangle’ (Accademia, Venice). Here he provides one of his simplest illustrations of a shifting ‘centre of magnitude’ without a corresponding change of ‘centre of normal gravity’. This remains passing through the central line from the pit of the throat through the umbilicus and pubis between the legs. Leonardo repeatedly distinguishes these two different ‘centres’ of a body, i.e., the centers of ‘magnitude’ and ‘gravity (Keele 252).”
This image provides the perfect example of Leonardo's keen interest in proportion. In addition, this picture represents a cornerstone of Leonardo's attempts to relate man to nature. Encyclopaedia Britannica online states, "Leonardo envisaged the great picture chart of the human body he had produced through his anatomical drawings and Vitruvian Man as acosmografia del minor mondo (cosmography of the microcosm). He believed the workings of the human body to be an analogy for the workings of the universe."