Microsoft Gaming boss Phil Spencer seemingly teasing Xbox's "Keystone" streaming device

Folks on the internet seem to think Xbox gaming boss Phil Spencer is teasing Microsoft's "Keystone" streaming device. While looking over a tweet from the executive showing off shelves of items, on the very top shelf there's a small white box that looks similar to a mini-Xbox. Even the power button looks similar. This has led many to believe the small box is the streaming device Microsoft has in the works under the codename "Keystone".