I don't believe it was a paid contract for a client. It would have said so. 11 months? Everything about it smacks of a publicity stunt (which clearly worked so in that respect it has probably paid off for the artist). As Gmanx just said : "unveiled at Photoshop world". People always overestimate how high a dpi is needed…
Whatever happened to just painting in one layer? I know I fall into the trap of having too many layers, but I've found that when you have that much junk to deal with and organize, and keep track of, you lose sight of the end result and it gets frustrating. A few layers or so for a 'painting' is all that's needed. I just…