Some iPhone Duo owners have discovered that Apple's first foldable is missing a pretty important appearance setting that you can adjust during the initial setup process, but not afterwards. Display Zoom setting on iPhone 18 Pro (left) vs. iPhone Duo When you first set up an iPhone Duo (or indeed any iPhone), an option screen called Appearance lets you choose how you would like text and icons to look on the screen. You can choose Default, Medium, or Large.