A new leak of internal documentation has provided a deeper explanation of the Microsoft Courier. The dual-screen tablet prototype has a fundamentally simple interface with two-finger multi-touch gestures: besides usual navigation, it would let users tap-and-hold to clip a photo or other object and a two-finger swipe left or right to move that object to the opposite page. The pen also has two buttons and an "eraser" to both switch between drawing styles as well as to remove recent changes.

The Gizmodo tips also elaborate on the concept of the Infinite Journal, which compiles all the clips, notes and other information in the Courier. It centers on a Smart Agenda that provides a calendar overview, messages and data like weather. Microsoft would have users navigate quickly between pages through a Cover Flow-like 3D page view with a timeline; the web browser would have a similar metaphor. A separate Library section would handle both apps and media in a central bookshelf location and implies that e-book reading would play a significant role.

Courier has been characterized as a prototype concept that, if it reaches a more definitive stage, may undergo significant changes. It's widely considered a test vehicle for Microsoft's future touch interface concepts and a possible preemptive response to a possible Apple tablet.