This original iPhone 2G prototype was used for external (outside the company) testing and was not loaded with the official iOS interface. Instead, it ran the “skankphone” testing interface (see “skank is the new black” in small print on the picture in the auction listing).
If you look at the 6th picture, you’ll see the icon view, which features a Cheerios box as an icon for the serial number. Cereal for serial, get it? Heh.
I love looking at these old phones. Amazing how far the world has come since the original iPhone was introduced.