It's really just an outline on top of a black background, however Samsung revealed just enough to make comparisons to its Galaxy Note Edge. This would suggest that the Galaxy S6 will sport the same type of curved display, which wraps around the side of the handset. Here's a look at the Galaxy Note Edge:
Notice the silver bezel that runs along the side and then curves up on both ends of the device. Now take a look at Samsung's teaser image:
هل هذا قصد سامسونج في اعلانها الاخير؟ 😏👌 pic.twitter.com/TQnFuqiu5y— Hamad A. Alajmi (@7mdalajmi) February 2, 2015
There's also the question of what processor will be inside. Samsung reportedly rejected Qualcomm's Snapdragon 810 chip due to overheating issues and is planning to use its own Exynos chips, though there are also reports that Qualcomm is working on a revised version of its Snapdragon part for Samsung.