Change your Apple Account photo on iCloud.com
Your Apple Account photo appears on your iCloud.com homepage. You can change it at any time.
Go to icloud.com/settings, then sign in to your Apple Account (if necessary).
Tip: If you’re already on iCloud.com, you can also tap your Apple Account photo or in the top-right corner of the window, then tap iCloud Settings.
Tap Change Apple Account Photo, tap “Browse your device for a new image,” then follow the onscreen instructions.
To change other settings related to your Apple Account, go to the Apple Account website.