The promotional image below shows the NH-L12 stripped of its fans, revealing just the cooler itself. Here we can see the four heatpipes that carry heat from the base up to the array of fins which will eventually be sandwiched by the two fans. You can just make out two voids in the array of fins, and these are the locations where you pass the included screwdriver through in order to secure the cooler to your motherboard. Everything lines up perfectly so you can install it with both fans installed, and you have good visibility looking straight down to make it all happen.
The next image provides a top down view of the NH-L12, where we see the unmistakably Noctua colored fan. Unfortunately the fan blades would have to be spun a few degrees to reveal the through holes described in the previous paragraph,
The below left image shows the cooler from the side where the heatpipes travel, and provides a good reference for the overall height. At about 3 5/8" tall with the top fan installed it is fairly compact... And you can take about an inch away from that if you only use the lower fan. The below right image shows the cooler from another side, and this view gave me some concerns since you can see that the stack up of fins and fans is not centered above the cooler's base. Motherboards are designed with clearance in close proximity to the CPU socket, but once you start getting away from that area, all bets are off when it comes to possible interference.
The next two images show the base of the cooler, where we find a large smooth surface designed to mate up with almost any modern processor. It is shipped with a plastic shroud over it in order to make sure it gets to you unblemished.