The Optimized for Xbox Series X|S icon means the developer has done the extra work to take full advantage of the unique capabilities of Xbox Series X|S. In addition, Smart Delivery ensures you are getting the right version of your game no matter which Xbox you're playing on.
Does Xbox One S mean slim?
You can think of it as the Xbox One Slim: it's physically smaller (40%, according to Microsoft, and who are we to argue?) and doesn't have that great big power brick hanging off it. The Xbox One S is not compatible with Kinect out of the box; you'll need an adapter.Aug 1, 2016
Does Xbox One S include vertical stand?
The vertical stand will not be included with every Xbox One S console. Microsoft recently unveiled a new, slimmer version of its Xbox One console at E3, dubbed the "Xbox One S".