While the original Surface used cameras to detect objects and input, the new design utilizes Microsoft's PixelSense, an infrared sensor system allowing each pixel to recognize colors, shapes, and touch. As demoed, the device can read the text on a piece of paper, presumably allowing it to scan text and pictures directly onto the screen for manipulation.
The physical design has been trimmed down as well trading the bulky tabletop-only layout for a new 4-inch form factor capable of wall mounting. The screen itself is covered by Gorilla Glass, a highly durable, scratch-resistant surface intended to guard against damage from heavy objects. This is no surprise considering the original Surface saw its most notable use inside businesses and restaurants and not in homes. Still, the new version will be available in stores according to a Microsoft blog, giving the possibility of a reduced price tag for home users.