Nokia’s upcoming flagship Windows Phone, the Lumia 900, has been revealed in a leaked promotional video aimed at developers. First discovered by Netherlands-based All About Phones, the video was accidentally posted to Nokia’s public YouTube channel before being marked private. The video offers very little in the way of details, though it does show an image of the sleek Windows Phone next to the text, “When you bring together Nokia’s stunning new hardware and a dynamic Microsoft OS you get amazing every day.” Nokia’s Lumia 900, code-named Ace, is expected to feature a 4.3-inch ClearBlack AMOLED display, a 1.4GHz processor and an 8-megapixel camera with Carl Zeiss optics. Nokia France boss Paul Amsellem on Wednesday alluded to the device while speaking with a French newspaper, but Nokia responded to reports by saying it had nothing to announce at this time. Nokia’s full promotional video follows below.