Many apps give you a different view when you rotate iPhone.
To lock the screen in portrait orientation, swipe up from the bottom edge of the screen to open Control Center, then tap .
The Portrait orientation lock icon appears in the status bar when the screen orientation is locked.
When you use iPhone 6 Plus or iPhone 6s Plus in landscape orientation, some apps have special layouts. These apps include:
Note: These special layouts are not available when Display Zoom is enabled.