Arcade Fire debuted the first single off of their forthcoming album today, but they didn't release it as a simple MP3 file. Instead, the band debuted an interactive short film called "Just a Reflektor" that turns viewers into participants in the video by allowing them to control virtual light sources through their smartphones. The film tracks the phone's physical position through each viewer's webcam, and it uses that position to simulate how it would illuminate the screen. The video changes course eventually, at times using the phone to control light being reflected off of mirrors or projected out of headlights, having the phone's speakers serve as an extra source of sound, or using just the webcam to bring the viewer into the film itself.

It's something of a surreal experience for the viewer, which isn't out of line with Arcade Fire's past interactive music videos. The band has also had interactive videos produced for two of its previous singles, "Neon Bible" and "We Used to Wait," the latter of which was part of Google's Chrome Experiments program. "Just a Reflektor" joins that program as well, and even has a page dedicated to explaining the web technologies that it uses to make the whole setup work. It also breaks several of the video's effects out on their own, allowing viewers to tweak how they react and play with them for as long as they'd like.