When you want to change the user accounts picture, you need to pick a different picture to use. Just click on the picture to select it. Then click the change picture button to use it.
How do I change the default picture in Windows 10?
1. You should click the Control Panel’s Add or Remove User Accounts button.2. Click the account you want to change.3. Click the Change Picture button.4. Select another picture.5. Click the Change Picture button.6. Click the Control Panel’s Close button.