This is the Xbox Watch. A thing Microsoft nearly made around 2013 to compliment it's plans to make a Xbox branded phone.
These images are via Suomi Mobiili and appear to show a Xbox branded smartwatch, with a heartbeat monitor and some sort of port. Rumours of an Xbox watch first appeared in 2013 although ultimately nothing was ever announced or seen.
According to Suomi Mobiili the device would have had a 1.5 inch touchscreen, and that port would have connected it to Surface tablets to charge and transfer data. Quite how it would have worked as an 'Xbox' device is unclear, and that might just have been an odd branding quirk. It's also worth noting that Microsoft made a move into the mobile space by announcing Smartglass in 2012 which leaves this 2013 prototype in a very odd limbo.