A little zooming photo shop magic reveals that it is a double-sole. "Double-sole" is a bit of a misnomer in that one of them is distinctively thinner on most models. In other words, they don't generally take two standard soles and literally stack them. Instead, the outermost one is a standard thickness, and the upper one is about half that. See this photo of your shoes zoomed in with the layers marked by red lines (click to enlarge):
Warning: Spoiler! (Click to show)
The uppermost layer is the welt, followed by the first sole, followed by the second sole.
There he goes droppin' some knowledge.
Thanks MWS, as always.