The XS Max is Apple's first OLED phone with Display Zoom
This feature, however, started lacking on Apple's notch-ed OLED phones, beginning with the iPhone X last year. Its successor, the iPhone XS, also doesn't sport it, but the iPhone XS Max is the first of Apple's new phones with OLED screens that allows you to turn on Display Zoom from Settings > Display & Brightness > View.
Needless to say, the feature it's a welcome addition to the huge 6.5" panel canvas, and brings a necessary re-scaling for better iOS app compatibility, as some aren't even tailored to the notch realities just yet, let alone giant screen diagonals and funky resolutions. Needless to say, the effect is not as pronounced as with Display Zoom when the jump was from 4.7" iPhones, but it still very noticeable as you can see in the screens here, plus it takes seconds to apply or reverse if needed.