The award-winning artist John Picacio has unveiled all twelve images, with commentary, on his blog. Not only does he describe the basic process, but he provides explanations about his inspirations, his views on the characters, and more. The detail with which he’s able to render characters is quite amazing.
Some truly amazing work here! Linda and I are especially fond of are his depiction of the Others (or White Walkers, as they’re usually called on HBO’s TV adaptation) and his Melisandre. Ice and fire, indeed. I’m also quite fond of his terrific depiction of the Red Viper taking on the Mountain that Rides.