How do I change the usernames and account pictures on my Acer Chromebook?
Account usernames and pictures are shown by default for the Google Accounts listed on the main sign-in screen. When you sign in to an account for the first time on your Chromebook, you'll be prompted to choose a picture to represent your account. You can take a picture using the webcam, upload a file, or choose from a range of colorful icons.
For more information about changing account pictures or hiding usernames and photos, visit Usernames and account pictures page.
For more information, visit the Chrome OS Help Center.