If you update the distro logo file, specified at "/etc/os-release", [System Settings -> About this system] continues showing the old logo. Even after reboot, or after updating the icon cache.
Work around: Remove: ${HOME}/.cache/icon-cache.kcache
The data comes from KOSRelease which lives in KCoreAddons; moving there so all users can benefit from any changes to this.
Please provide step by step instructions on how to reproduce this.
1. Read which logo is used at "/etc/os-release". 2. Figure out where's that logo file, either in (/usr/share/pixmaps) or (/usr/share/icons). 2. Change the logo file, preserving the name. You can use the command "sudo cp". 3. Go to [System Settings -> About this system].
That's an icon caching problem.