Apparently the mobile phone was purchased from eBay and came pre-loaded with the next version of Android on it.
That platform release would be Ice Cream Sandwich or Android 4.0 if rumors are to be believed and is expected to become official as soon as next month.
Google has already announced that they will be holding an event together with Samsung on October 11th and that event is expected to be dedicated to the unveiling of Ice Cream Sandwich.
The device that can be seen in the video below available courtesy of Engadget appears to be running under an OS build that is different from the Android 2.3 Gingerbread platform flavor that it usually sports.
Some of those who had a close look at the video report that the device appears to be running under a 3.x Kernel and that most of the UI elements are similar to the Honeycomb OS flavor.
On this list we can count the lockscreen dialog boxes and color scheme, icons, Recent Apps list with titles and thumbnails, the Settings screens, or the Google search bar and the voice-input button on the homescreen.
For what it's worth this might be nothing more than a well-designed elegant theme, one that makes the OS on Nexus S look more like the platform flavor destined for tablet PCs and the entire story could be nothing but a hoax.
However there is also the possibility that the device is indeed powered by a newer build of Android and that all the new elements that can be seen in the video below will make it to the final flavor of Ice Cream Sandwich set to arrive before the end of the year.
While keeping the entire story in the rumor section we'll keep an eye out for more details on the upcoming platform version from Google so stay tuned for additional info on this.