This happens because the app-indicator searches for an icon named 'appointment-soon' and if that's not in the current theme it then searches for 'appointment' before it goes to the next Theme.
The call is g_themed_icon_new_with_default_fallbacks followed by gtk_icon_theme_lookup_by_gicon.
It seems like it should search all the themes before falling back.
PS. This basically stops any app that wants to include its own icons using app_indicator_new_with_path since the path is appended as a last Theme if they say 'myapp-idle', but the default theme has an icon called 'myapp' it will always use 'myapp'.
This happens because the app-indicator searches for an icon named 'appointment-soon' and if that's not in the current theme it then searches for 'appointment' before it goes to the next Theme.
The call is g_themed_ icon_new_ with_default_ fallbacks followed by gtk_icon_ theme_lookup_ by_gicon.
It seems like it should search all the themes before falling back.
PS. This basically stops any app that wants to include its own icons using app_indicator_ new_with_ path since the path is appended as a last Theme if they say 'myapp-idle', but the default theme has an icon called 'myapp' it will always use 'myapp'.