The final thumbnail choice:
And the finished linework and initial colour/lighting pass:
Here's the progress with the Share One Planet piece. For a while I couldn't make my mind up between the two compositions in the thumbnail. A tiny part of me still loved the original on the left, but couldn't say why, since the right hand side was the obvious choice for composition... the lines and the way the eye were led around the image followed every rule in the book. And despite a post on dA where pretty much 100% of people told me I should go with the right hand version of the two final thumbnails, in the end, some advice from a great Art director and friend (thanks Andy!) gave me the nudge of confidence to follow that gut instinct that said I shouldn't go with the 'safe' option. The left felt edgier, and he pin pointed that the way the eye was lead up the image was in more of a zig zag, whereas the right was more flowing, in keeping with the lines of the animal. The focus of the piece was the cat's face, everything led up to it, and thinking on it now, that zig zagging feel is the sort of eye movement you might get from a frightened ibex knowing there's something slightly amiss.
So, the more I work with this piece the more I feel like I have made the right decision, if only for myself!