Look at the picture closely, there is a "Swoosh" on the top and bottom of what seems to be the DISH Network logo.
If this was the beginning of a logo being painted on the roof, then there would not be (2) Swooshes, since that was part of the old logo. The newer updated DISH Network logo only has a Swoosh on the top!
I think there was a DISH Network logo painted on top of the Pepsi center at one time, but that deal expired and it was painted over, and what your seeing now is that layer of paint fading away exposing the old logo under the layers of paint.