The text marked with this symbol that will enable after the upgrade of the Auro-3D.
You can experience the best performance of Auro-3D if you install front height and surround height in addition to standard 5.1ch. The Setup Assistant will lead you to this setting.
AVR also can play Auro-3D using standard 5.1ch and front height speakers. If you install any height speakers instead of surround height speakers, you can set the speaker configuration in Setup Menu.