Quick, from the photo above, can you tell which Apple TV is the third generation device? Externally, the Apple TV 3rd generation is virtually indistinguishable from the Apple TV 2nd generation. The new device keeps the exact same dimensions and mass, in fact, during my testing the only way to tell the two apart was to compare the model number at the bottom. This is pretty unsurprising for an Apple product cycle, where you see successive generations inherit the same external design even as internals evolve or change dramatically. On the box, the new Apple TV 3 now includes both a 1080p marking and an Energy Star logo, something the previous model didn't.
Less than four inches square and an inch tall (the exact size of the 2nd generation Apple TV) the small but mighty Apple TV 3rd Generation adds the ability to play 1080p HD content.