How Do I Change My Profile Picture in Outlook?

Outlook 365 (Web Version)

Click the picture in the top right hand corner. 

Click the 3 dots in the bottom right corner of the box.

Click "My Office Profile"

Click the camera icon and change photo

Office 365 (Desktop)

Click "File" and select "change" 

Click "Upload a new photo"

Select and fit your photo, then click apply.