Q: Why doesn't my airplay icon display when trying to screen mirror using Apple TV?

Requirements for using AirPlay

If you go to Apple menu > System Preferences, click Displays, and don't see the option to "Show mirroring options in the menu bar when available," your Mac doesn't meet these requirements.

Minimum requirements if your Mac and Apple TV are on the same network:

• Apple TV (2nd generation or later) with the latest Apple TV software
• For mirroring your display or extending your desktop, any of the following Mac computers with OS X Mountain Lion v10.8 or later:
  • iMac (Mid 2011 or later)
  • Mac mini (Mid 2011 or later)
  • MacBook (Early 2015 or later)
  • MacBook Air (Mid 2011 or later)
  • MacBook Pro (Early 2011 or later)
  • Mac Pro (Late 2013 or later)