iPhone Duo can be used fully open, closed, partially folded like a book, standing like a tent, or placed down in a seated position. Each position changes which display faces you and can make features such as StandBy, Smart Take, FaceTime and video playback more useful.
The key difference is which screen you want to see. A book-style partial fold keeps the inner display facing you in landscape, a tent position puts the outer display toward you, and a seated position presents the inner display in portrait with the lower half acting as a base.
Knowing which iPhone Duo position to use can also save you from reaching for a separate stand when watching video, taking hands-free photos or making a FaceTime call.
Partially fold iPhone Duo along its hinge so it is open like a book and the inner display faces you in landscape. You can hold the phone in this position or place it on a flat surface.
Apple uses this position for features including StandBy and Smart Take. It is particularly useful when you want the larger inner display facing you while the hinge supports the phone at an angle.
Partially fold iPhone Duo and place it down like a tent so the outer display faces you in landscape. The two halves of the phone support each other, allowing the device to stand without a separate kickstand.
This position is useful for viewing information from a distance in StandBy. It can also face the outer display toward a person you are photographing, allowing features such as Kid Cue and the subject preview to make use of the second screen.
Partially fold iPhone Duo and place the lower half flat on a surface so the upper half of the inner display faces you in portrait, similar to a small laptop.
Apple recommends this position for watching video from a distance, with playback controls available on the lower portion of the device. It is also useful for FaceTime calls because iPhone Duo can remain standing on its own while you talk.
Fully opening iPhone Duo gives you the entire inner display and is the best position for tasks that benefit from maximum screen space, including reading, watching content and using two apps at once with Split View.
With iPhone Duo folded shut, the outer display is designed for quick everyday tasks without opening the larger inner screen. This is the most conventional phone-like way to use the device when you do not need its expanded display.
Apple illustrates the different positions in the iPhone User Guide. The Apple Post’s complete iPhone Duo guide covers the foldable design, inner and outer displays and the software features built around them.