Profile pictures rule the roost everywhere. You have profile pics not just on Facebook and Whatsapp but also on Mac and PCs. It's mostly a cosmetic feature but it helps people personalize their Mac OS.
Your Mac lets you set a profile pic when you configure it for the first time. Many people usually pick one of the default pictures that OS X provides. Some skip this part (because it's optional and you can change it later). If you're new to Mac and want to set/change your profile picture, here's how to do that.
How to Change the Profile Picture on Mac:
Step #1: Click on the Apple Menu, then on System Preferences.
Step #2: Click on User & Groups
Step #3: There's a picture icon next to “Change Password” option. Click on that icon.
Step #4: This brings up a lot of options and pictures to select from. The defaults are system pictures. You can also select pictures from iCloud, Faces (iPhoto) or click a picture right now with the Camera option.
Step #5: Hit “Done” once you are done selecting your new profile picture.
But what if you want to select a picture from some other folder? If you want to set a totally custom picture as your profile picture, that can be done too. Almost as easily.
Step #1 &2: Same as the ones above.
Step #3: When you see the User & Groups window, drag the picture you want to have as profile picture into the small square where the current profile pic is displayed.
Step #4: Click on Done and you're set.