The above toolbar should be visible in all GNOME discourse web pages. It disappears when we move into a topic. If there are space constraint issues, at least a mini version of toolbar ( which can expand fully when clicked ) should be made available.
I doubt that it is, if only because the container div for that page element is <div id="list-controls">, which is not present at all on individual topic pages.
In the Discourse model it doesn’t appear to be a toolbar so much as a list header, so it only appears when viewing a topic list.