I don't think this signifies spotlight searching on the iPhone at all. I recognize it as the image that shades over the iPhone screen when an alert pops up. For instance, if you are browsin the web on iPhone and a text message comes in. The blue alert sits in the midle of the screen, while the "spotlight-full" image is ghosted over the rest of the screen.
Hopefully one day we'll get an actual filesystem that lets us save, browse, and search files. But until then, I don't think what was found in the article linked above is any sign of what's to come.