Here's a couple quick shots from the Damen Brown Line station at 4643-47 N. Damen Ave.
The CTA Brown Line Capacity Expansion Project (you'd think all the consultants the City hires could come up with a snappier name) not only brought better station facilities, but they also brought public art displays.
Again, I think this a nod towards European sensibilities in regard to public art... the Mayor went to France and came back with Millennium Park. I'm not sure who made the decision for the public art installations, but it is consistent with an overall theme to "class up" the city. And, a pretty simple idea that delivers big.