The video is from the @surface Twitter account. As usual, start playing and then maximise for best effect:
Pretty cool. Part of me wants to try the Surface Duo so badly, for the unique two-screen workflow. The other half says not to be silly, you can't get it outside the USA yet and besides it's a lot of money for an Android device with underwhelming specifications. Still, we should have actual reviews to link to tomorrow, since the original Duo review seeded devices have their NDAs expire. I'll round up the best video reviews then.