I have looked into the question of what address one enters in the URL Field to enable one to use these Logos.

This is all presupposes that one has Fast Dial set up as home in the fast dial folder in Bookmarks menu.

(Please see previous thread for method employed below)

My impression so far:

If one enters the below addresses as URL for a cell then these will then open like Folders.

It is my impression that:

chrome://fastdial/content/fastdial.html?folder=1

opens the All Bookmarks Folder (will appear in fast dial mode)

Includes on Fast Dial Page (cells)

Bookmarks Menu
Bookmarks Toolbar
Tags
Unsorted Bookmarks

(so above logos could be used here !)
So one could stop there and use the logos on this fast dial page.

However it is also my impression that

chrome://fastdial/content/fastdial.html?folder=2

opens bookmarks menu (will appear in fast dial mode (cells))

So this will include as cells all the folders in bookmarks menu

It is also my impression that:

chrome://fastdial/content/fastdial.html?folder=3

is Bookmarks Toolbar (also shown in fast dial mode)

It is also my impression that:

chrome://fastdial/content/fastdial.html?folder=5

is unsorted bookmarks (also shown in fast dial mode)

It sort of follows that

chrome://fastdial/content/fastdial.html?folder=4

is tags (not yet confirmed)

Not so sure yet about recently bookmarked as it is a subfolder of bookmarks Menu, so can be reached from there.

Please use the back cell in these bookmark folders with caution.

It will not take you back to the fast dial root, as you are now in bookmarks folders and no longer in fast dial.
So you are now in the bookmarks hierarchical structure.
This is a little confusing at first !

many thanks

For your possible interest also:

Bookmarks Manager

Chrome URL
chrome://browser/content/places/places.xul
this works fine (takes one directly into bookmarks)

However this does not open Bookmarks in Fast Dial mode.

Regarding use of chrome xuls in Fast dial please see here: