Looking at the top of the stack of fins, you will see the Noctua name and logo with six pipe ends on either side of it to hopefully make things really efficient with heat dissipation. You can also notice the wide V created in the middle to allow the fan some room to build up speed before entering the fins.
From this angle you can see that the center of the cooler is mainly flat as it works its way outward. Once between the second the third set of pipes, the fins are irregularly shaped to rough up the air flow in this area to improve the transfer of heat.
At the other end of the cooler you have this two piece base assembly. This design makes it so the hardware to mount the cooler comes attached to the top section, and under it the six pipes are soldered to it and the lower section of the copper base. Once assembled, the pipes and base are nickel plated prior to having the fins pressed on them.
Laying the cooler over to get a look at where the fins are pressed on, you can see some concessions had to be made. There are holes in the lower fins for the inner most pipes to get through, as well as being cut short, so the outer pipes can make it smoothly to the outer edge of this design.
Under the base plate, there is solder holding these six pipes into place. Rather than filling the entire gap with solder, as the pipes bend and begin their trip away from the base, they do come away from the base, but the heat is already transferred to them long before they exit the base.
Since the base is milled and left machined with no extra polishing involved, you are left with fine grooves, but also a very flat and level surface to mate up to the CPU when it gets installed.