These aren't the exact same picture, but it would be difficult to argue that they aren't from the same game. The pic on the top is the mystery photo and the pic on the bottom is from the 2006 SMU game. You can tell it's not the same pic by the cars on the highway, the player positioning on the field, and the line of sight when looking at the north visitor's side light grid vs. the green & white water tower in the distance. However, the crowd looks similar (minus the suspected photoshop job in the North end zone). What really makes it obvious it is from the same game is the cars in the parking lot.
Also, on the grassy knoll, you can see a tent in the bottom picture that is obscured by the score board in the upper pic.