If there is this sign, it means that the portrait screen lock is turned on, and the mobile phone will not switch between portrait screen and landscape screen.

If there is no sign, it means that vertical locking is turned off. At this time, if you turn the phone 90 degrees, the screen will also rotate, which is suitable for the direction of the human eye.

Contact information:

You can turn it on or off by sliding your finger from the net at the bottom of the screen and clicking the circular icon.

Extended data:

A vertical directional lock is a directional lock. Always keep the screen upright, no matter how you shake it, it won't rotate.

"Vertical lock" button, if you are lying in bed, you can also hold the phone vertically without changing the direction of the content.

For example, if you are reading a book, reading a short message or reading a web page, you can unlock this vertical screen lock if you lie down but don't want to automatically turn into a horizontal screen due to gravity induction. I can't use gravity sensing to turn the screen. I like this function very much.

Double-click the Home button and swipe right at the bottom. Is there a lock icon in the lower left corner? Clicking on it will prompt you to lock vertically. If you want to cancel, just press the HOME button twice to pull to the right, and then click Close.

References:

Celestial pole How does com-iPhone turn off screen rotation?