When plugging into a TV or projector, Mac laptops will automatically span the desktop to the “second” screen that was just plugged in. These instructions will show you to configure your Mac to show the same thing on both displays or "mirror" them.
- Connect your Mac Laptop to the TV or Projector.
- Go to the Apple Menu, then System Preferences.
- In System Preferences, click on Displays.
- Click on Arrangement.
- Put a check in Mirror Displays.
- The same content will now be displayed on your laptop screen and on the TV or Projector.
Note: This setting will be remembered, so once set, it should not need to be changed again.