Dissected
Here we see the 92mm Xigmatek fans that the outer shell hides.
These images provide a much better idea about how the aluminum fins are arrayed. Approximately 50% of the fin array, the center portion of each side, is actually closed off in order for the air to pass along twice as area as it otherwise would if the fins were open. The very center of the entire array allows air from both fans to pass directly onto the base of the heatsink.
Installation
NVidia chose to directly expose the mirror finished G92 core on the 8800GTS 512MB without applying an IHS.
The first step is to apply the two little wings flanking the base of the cooler. The next image shows the thermal paste application and the area of the base the G92 core takes up.
Here you can see the screws from the base on the other side protruding through the four holes around the core. The next image shows the nuts installed to secure the cooler to the card.