A depth sensor is a device that measures how far away objects are from it. It helps to create a three-dimensional map or image of the surroundings by determining the distance between the sensor and various objects. Full definition
However, the big feature is its 4 megapixel camera with a massive sensor, a dedicated motion sensing camera, and depth sensor for scanning locations in full 3D. (androidcentral.com)
We also found its portrait mode to be better thanks to the secondary depth sensor, and videos had better colour reproduction. (gadgets.ndtv.com)
We can expect that it will do that eventually given the fact that it really only relies on the front - facing camera and no additional hardware like 3D depth sensors. (sammobile.com)