There were a slew of different prototypes for the Xbox One before Microsoft settled upon its current form, according to new information from Microsoft’s Xbox design team and creative director Carl Ledbetter. A picture shown by Ledbetter at Microsoft’s Worldwide Partner Conference displayed the incredible variation among the prototype designs.
“We wanted to make it simple and elegant, and we wanted it to be crafted and tailored, so it’s all about quality,” said Ledbetter.

The design team of about 30 people started by sketching out versions of the console and sent them to an in-house modeler to build prototypes. After that, they tested them in various environments to see how they would fit in. They then determined how internal parts would fit into the console. Ledbetter said that the design team also went through more than 200 different controller designs before accepting the current Xbox One controller.
Source: Polygon