The PNG'ified buttons had some smoothing affected to them, to help define them from the original interface artwork.
When highlighting on the original interface, the images show a marked difference because of the way they are box-shaped. This difference in "contrast" over the original interface (which was by design) shows that it has indeed loaded the PNG element for that interface portion. The main-hall EFF for the starmap shows a "throbbing" Gamma Draconis.
The PNG images are not defective save for the original Nameplates where the Transparent PNG's were made in photoshop.
As for the creator of the linked Test-Package, that would be me.