1) The contrasts in the proportions have been toned down a bit.
The faces take up a bit more space in John's heads than they do in the originals. Angles and lines of action are slightly less extreme than Harvey's.
2) The finished drawings are less organic - less flowing.
the lines and shapes should wrap around the forms more gracefully and less stiff.
3) I can't really see the constructed forms underneath the first one and that leads me to suspect that John might have just copied these by eye using the negative shapes as guides, and not constructed them first. And then drew in the construction lines afterwards. I could be wrong; that's just what it looks like.
I wouldn't think that if the details flowed more around the bigger shapes.
I should be able to see the head shape all the way around under the hairs, ears and shoulders.
same with body shape, feet, anything that is a form.
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