I’m using modx-2.0.8-pl with CentOS.
When I was using modx-1.0.x, there were various icons on left file trees. For example
If the object is,
Folder: media/style/MODxCarbon/images/tree/application_double.png

Normal document: media/style/MODxCarbon/images/tree/application_html.png

Restricted folder: media/style/MODxCarbon/images/tree/application_double_key.png

Restricted doc: media/style/MODxCarbon/images/tree/application_html_secure.png
For modx-2.0.8, it seems there are various icons in manager/templates/default/images/restyle/icons/
However, when I created restricted folder/doc which are associated to resource group, normal icons of file or folder are used like this.
Restricted folder: manager/templates/default/images/restyle/icons/folder.png

Restricted doc: manager/templates/default/images/restyle/icons/page_white.png
I believe for these restricted objects, some special icons such as "page_white_key.png" should be used.
(Unfortunately, I don’t find any suitable icons for "restricted folder")
If anyone know why, please let me know.
otherwise I think I should create a new ticket for this enhancement.