Vent-based geometry?

I went to the Seattle Central Library the other day and took my camera along to take pictures, as I'd been planning to do for some time. The library building was recently built and is a big, abstract, glass affair with lots of exposed industrial building materials and severe lines. It's very cool, and seems to be a big success; every time I've been there, the building has been quite busy, with people browsing through the stacks or using the public computers.

These vents caught my eye; they're just air outlets, I think. The latticework you see in the background is the shell of the building; you can see that it was raining quite heavily that day.

The gloom and rain outside made it quite dark inside, despite the masses of glass, so this was taken at ISO 1600, which is the highest sensitivity I like to use on my camera, although it will also go to 3200. Even at web resolution, you can see that there is a texture to the image. Like I was saying before, though, I usually find this unobjectionable, and sometimes even attractive.