I live in the inner-ring and have for a very long time. They probably closed Memorial Drive and went into "Fair" mode. That picture looks like all the ones you see for the fireworks. As a user of Photoshop, I don't think it's faked. The block between the hotels in front of the Old Courthouse is a park. It's Saturday, it's beautiful outside and people went. They probably drew from both sides of the river, JeffCo, maybe even as far as Boone County.
I don't like it, but give credit where credit is due - it was one heck of a stunt.
So then where are the trees in red in this picture...
...in this picture?