A 2010 Sony patent dug-up by VentureBeat shows what looks to be a touchscreen handheld controller similar to the one Nintendo introduced for Wii U.
Called the "Position-Dependent Gaming 3-D controller, and Handheld as a Remote," the device appears to act as a controller which allows interaction between what's depicted on its screen those on the television screen.
Here's a description of the device according to the patent information:
"Methods and systems for using a position of a mobile device with an integrated display as an input to a video game or other presentation are presented. Embodiments include rendering an avatar on a mobile device such that it appears to overlay a competing user in the real world. Using the mobile device’s position, view direction, and the other user’s mobile device position, an avatar (or vehicle, etc.) is depicted at an apparently inertially stabilized location of the other user’s mobile device or body. Some embodiments may estimate the other user’s head and body positions and angles and reflect them in the avatar’s gestures."
Through the USPTO link above, there are various descriptions of what the device could be used for, and how it goes about doing what it does. Other than being described as a mobile device with position-dependency, there's not much else to go on - it could be some handheld device, or a controller.