Can't Update Display Image in Messenger for Mac
This article describes what to do when users experience issues with updating their display image in Yahoo! Messenger for Mac. Often, it appears that you have updated the display image successfully, it will not appear in some windows, or after the computer has been restarted.
If you are unable to change your display image using Messenger for Mac we suggest that you follow the steps outlined in the help article, Correcting Yahoo! Messenger Errors on Mac.
After you follow the steps outlined in the article above, we then recommend that you uninstall and reinstall Messenger, for help visit How to Uninstall Yahoo! Messenger for Mac.
If you are still unable to change your display image after uninstalling you will need to clear your Messenger cache.