Look, we're as excited as you guys when headlines pop up across the Internet stating that the Lumia 925 has a notification light and the Windows logo flashes in the attempt to grab the owner's attention, but we're not convinced. And neither is Nokia (seriously, we've asked numerous times). That said, we've previously seen in person this blinking Windows capacitive key back when the Lumia 925 was announced (alongside the Lumia 928), but we were informed that it's simply related to debugging (basically the current power-state, blinking was a low-cycle).
We've not noticed any flashing lights on our Lumia 925 unit either, unless you're speaking about the proximity sensor. No matter which setting we attempted to manipulate, no matter how many times we requested friends to send across photos, SMS, emails and more, we just couldn't get the desired results. This was until today when we completely drained the battery and allowed the Windows Phone to shut down to wait until we located a power socket. When plugging the Lumia 925 in, we noticed the Windows logo started to flash.
What was the cause? We're not sure. As we speak, we're draining the device again to see what happens when we insert the USB cable. But it could well be that we're looking at the new way for a Windows Phone to alert the user that there's not enough charge to boot i.e. this is really a new GDR2 "feature", but since we have no other GDR2 phones, we can't compare.
This could be nothing, though. Nokia can't confirm anything for the time being, so we'll keep our eyes open for any details that may emerge and we will certainly reach out for confirmation on what we're looking at here (many have published footage of the flashing while the device is currently powered - yeah, we're scratching our heads).
We'll have to see what Microsoft has to say about a potential software update that enables such functionality. While we attempt to get some concrete details, if you own a Lumia 925: have you noticed the Windows key flashing at all through use, particularly when it's drained of power? If so, let us know in the comments.
Update 4:30PM ET: Mystery solved. While many on Nokia's own team don't know about this feature, it was described in a video (above, cued at about 13m, 33 s) with some product managers from the 925. Our original hypothesis was right that this is just a visual indicator to let you know that your completely dead Windows Phone is in fact, receiving a charge.
Up until now, if your phone ever completely died and you plugged it in, it could take upwards of a few minutes before the display would even turn on. That has probably made many people nervous, hence why Nokia made this feature. Thanks, Michael M., for the tip!