What is mirror my iphone?

Hi

The meaning of the mirror my iPhone setting for Apple Watch varies depending on the specific context.

Generally speaking, when enabled, your Apple Watch will provide the same notifications or behaviour as your iPhone is configured to deliver.

For example:

Mirroring Notifications will deliver the same notifications on your watch as would otherwise be delivered on your iPhone.

For Do Not Disturb, Mirror iPhone means that enabling / disabling Do Not Disturb on one device will also automatically enable / disable it on the other.