Windows Phone 7 Mango caught on video?

The folks at Pocketnow recently featured a video showing a developer team DFT (Dark Forces Team) showing off the Windows Phone 7 NoDo update running on a HTC HD 2 phone. In the video, another phone was caught on camera towards the end, and if you look carefully, you’ll notice that there’s an extra icon in the programs list screen on Windows Phone 7. Now there’s no official confirmation on what the button does, but people are speculating that it might belong to the Windows Phone 7 Mango update coming later this year. And if that’s the case, would it mean that DFT already has their hands on a leaked version of the build? Or could it be a homebrew customization from them? Hit the break to watch the video in question: