
Historically, when applications set "image-data" they expect it to show up as an icon. So we display it as such if an icon is not specified with an "app_icon" argument to Notify(). We also use "image-path" for an icon if an icon is not specified. We only display a large image specified with "image-data" or "image-path" if an icon is also specified. https://bugzilla.gnome.org/show_bug.cgi?id=659158