After a teaser video that hit UK TV over the weekend , Nokia took to the stage in London just now with the assembled press pack expecting the unveiling of a new 41 MP flagship Windows Phone.The Lumia 925 doesn't quite boast those kind of specs  just a 8.7 MP camera on board  but the device does represent yet another step forward in the Finnish firm's quest to take on Android and iPhone.Indeed, in some respects, it's also something of a departure for the Lumia range. For one, it's metal.The new metal band casing is designed to act as a "great antenna", according to Nokia's Jo Harlow, though it also has visual benefits, making the device look more aligned with its largely metal-based rivals.However, for those who love Lumia's colours, a snap-on plastic back can be picked up in a range of shades that enables the device to charge wirelessly.Spec wise, Lumia 925 appears competitive, boasting a 4.5-inch ClearBlack AMOLED display and a focus on what Nokia claims is "market leading" imaging technology  anyone who has sampled the device's camera will attest to that.Backing this up is a new first-party app created by Nokia's imaging tech team called Smart Camera, which allows the 925 to take a vast array of action shots, allowing users to edit them on the fly.Adding to the imaging focus, Nokia has also landed an exclusive Hipstamatic app also designed to appeal to camera buffs.This and other platform advances will also be delivered to existing Lumia devices this summer in a firmware update called Nokia Lumia Amber.That means there shouldn't be too much device envy from existing Lumia owners, with the Lumia 925 launching globally from June. Nokia has partnered with T-Mobile in the US for the launch, China Mobile and China Unicom in China, and Vodafone across the UK, Germany, Italy and Spain.