Strange white blinking light

[unitedearth]

I've come across many iPhones and I've never seen this.

http://www.youtube.com/watch?v=rMXlC...e_gdata_player

Skip to 1:51
Is this 3G or 3GS exclusive?


Edit:
Looks like I found the cause; infrared.

After some research, I found that cameras can see infrared beams. It's simply the sensor adjusting to the light. You cab even test this by holding a camera up to the phone and hovering your hand over it.

[DanTheManMS]

More than likely it's the proximity sensor, the thing that turns off the screen when you hold the phone up to your face so you don't accidentally press buttons with your cheek. It probably checks for the infrared reflection percentage and turns off the display accordingly.

EDIT: to further clarify, most webcams and cheap digital cameras don't have proper infrared filters in place, so they can pickup infrared signals that the human eye can't see. Try it with the Wii "sensor bar" if you'd like. You'll see that it doesn't sense anything at all, but in fact is just a few arrays of infrared LED lights, which the Wiimote infrared camera receives and uses to determine its position in 3D space.