The component is designed by default to be unobtrusive, so you trigger a modal by tapping the grave slash ` character on your keyboard. Alternatively, you can enable a trigger button in the UI by toggling a theme setting.
Once the modal appears you have access to some common actions, links and settings that you might typically need while developing with Discourse.
Right now the header icon always shows. A small improvement could be to only show it to admins. So when browsing the site as a regular user the look is not tweaked.