Which came first?

I spotted this wall on April 3rd at the northwest corner of 7th and Hoff, a block east of 4th Avenue:

If you look closely (you can click for a larger view, if you'd like), there are a few different layers: a block wall partly painted tan, but partly with a mural on it, then with another smooth tan layer on top, then signs and equipment on top of the rest as if the rest weren't there… Hello?