Returns the object "type" of the "image".
Note: If the root object is a video object then If a mediaplayer is enabled a sub-type of video or audio will be determined from the suffix. If it is not one of the known suffixes or if the mediaplayer is not enabled then 'other' is returned as the object type. Pure images return empty for an object type.
Author: Malte Müller (acrylian)
Located at zp-extensions/tinymce4/plugins/tinyzenpage/tinyzenpage-functions.php