The API (Liblindicator) which the inidcator-sound uses expects a GtkImage as the icon. GtkImage does provide the same fall back mechanism which Sebastian has pointed to above with GtkIcon. It is a known issue across all indicators and one which will need to be resolved shortly.
The API (Liblindicator) which the inidcator-sound uses expects a GtkImage as the icon. GtkImage does provide the same fall back mechanism which Sebastian has pointed to above with GtkIcon. It is a known issue across all indicators and one which will need to be resolved shortly.