The concrete wall in the photo above is about as prosaic and forgettable as can be! It's part of one of the onramps to Interstate 5 and the West Seattle Bridge.
The vast majority of civil retaining walls, at least in Seattle are this way; utterly utilitarian, and devoid of any attempt at artistic treatment.
I remember driving along the German Autobahn in the early 1990's and being struck by how the retaining walls on the sides of the highway were colored and patterened! You don't see this much in the United States, but I did see quite a bit of it along the Interstate through the American Southwest. The great difference in civil vs. residential retaining walls is that by and large, civil retaining walls are much more structurally sound than residential retaining walls.