The filename and path of the file used for the thumbnail annotations (this could be the same as the image filename itself if the annotations are internal). If no file was used for annotation data, then this would be String.Empty.

public string AnnotationsFilename {get;}

public: __property string* get_AnnotationsFilename();

public:
property String^ AnnotationsFilename {
   String^ get();
}

'Declaration
 
Public ReadOnly Property AnnotationsFilename As String

'Usage
 
Dim instance As ThumbnailItem
Dim value As String
 
value = instance.AnnotationsFilename