The profile picture on your Mac (account icon), is the picture displays when you log in to your Mac.
Although your profile picture is typically chosen when you initially set up your Mac, you can change your profile picture at any time.
Here is how you change your profile picture:
1. Click on the Apple menu on your Mac’s desktop, then select “System Preferences”
2. Select “Users & Gruos” from the section “System”.
3. Click on the profile picture. You can now choose a new icon from the images presented or take a snapshot photo of yourself.