Another day, another purported Galaxy S III photo. We’ve been tipped with this convincing shot of the upcoming Samsung superphone, which follows the bullet points of the latest rumors. There’s reason to doubt, though: the phone in question is presented a little too perfectly for our jaded blogger eyes to believe. In any case, we should find out what the real thing looks like in less than a week when Samsung reveals the Galaxy S III at its London event on May 3rd.

So what’s wrong with this picture? Let’s start with what looks right: the sides are parallel and follow the general look of this leaked diagram, as do the home, menu and back buttons. The general layout is very similar to the Galaxy S II, which makes sense, except it’s got a larger screen and the control buttons, speaker and camera are squeezed into less space on the front panel.

So what’s wrong? One, the screenshot is suspect. Why take a photo of the SpeedTest.net app instead of the Galaxy S III home screen, complete with TouchWiz? Why do the wireless, battery and clock icons look identical to stock Ice Cream Sandwich, when we know that Samsung likes to add its own flair? And why, if the cameraman is taking a photo, is there a screenshot icon in the status bar? The simplest answer is that this is a screenshot taken from a Galaxy Nexus or another stock Android 4.0 ROM.

Issues with JPEG artifacts around the bezel and where the screen edges meet the casing are also suspect, though these could just be from the relatively low resolution of the photo itself. No mention of screen size, Exynos processors, camera megapixels or what have you accompany the photo. We’re calling fake on this one, though we’d love to be wrong. Just six days left before we see the real McCoy.