It's already been confirmed that the ways in which Series S and Series X handle Xbox One titles varies. Only the Series X will benefit from Xbox One X enhancements to existing games - which typically boils down to resolution boosts, higher quality textures and other graphics-driven effects. Xbox Series S brings its additional horsepower to bear in improving the experience of Xbox One S titles instead. This is more limiting in some respects (a game hard-coded to run at 900p will not run any higher on Series S, for example) but the new console benefits from increased resolutions in games that use dynamic resolution scaling, as well as improvements to texture filtering quality. Obviously, running games from solid state storage reduces loading times significantly, while the Auto HDR feature we've seen running on Series X also features on Series S - all games should present nicely on HDR screens, whether they natively support high dynamic range or not.