SUMMARY When the screen is locked, the default user avatar is a symbol for a person. The kickoff menu and the user settings use a letter on a colored background. STEPS TO REPRODUCE Lock the screen OBSERVED RESULT kscreenlocker uses an own default avatar EXPECTED RESULT The default avatar should be consistent across the whole desktop.
Changing it in settings seems to fix it. Maybe it only affects systems that previously used a .face.icon file.
*** This bug has been marked as a duplicate of bug 437418 ***