You can now watch Netflix videos in Dolby Vision high dynamic range (HDR) videos on the iPhone X, iPhone 8, iPhone 8 Plus and iPad Pro (2nd generation), following the release of iOS 11.
Some Android phones already enjoy HDR streaming, including the Samsung Galaxy Note 8, the Sony Xperia XZ and the LG G6.
HDR expands the range of contrast and color in images. Bright parts of the image can get much brighter, which appears to add a greater sense of depth to the video you're viewing.
Don't forget you'll need to have a Netflix premium plan to view videos in HDR.