Most smart phones utilize the top of the screen to provide the current information, or status, of the device. Due to the limited amount of space in this area, most of this information is conveyed through small icons or symbols. The lock icon on iPhone (the symbol with the circular arrow around it) has been in use for several different versions of iOS to indicate that the orientation of the device was locked to “Portrait”, but iOS 10 introduced a new lock icon that means something else.
You will see this new lock icon at the top of your screen when the device is locked. It appears on the lock screen, in the center of the status bar. You can see it identified in the image below –
Note that it appears near the portrait orientation lock icon, which is helpful in identifying that these two similar symbols have different meanings. If you then unlock the device, the lock icon disappears, the rest of the status bar icons shrink, and the time is displayed at the center of the status bar.
Do you find that your iPhone is locking more quickly than you would like, and that it is forcing you to re-enter your passcode, or use the Touch ID to unlock the device very often? Learn how to adjust the auto-lock setting on your iPhone so that it waits longer to lock. You can even disable auto-lock entirely if you would prefer to always lock the screen manually.