See a topic with many comments (i.e., [Writer] Padding inside columns).
When you go to the end (I pressed End three times, then scrolled up a bit), you see:
But if you click on it (and, again, scroll up a bit), you will see:
If instead of pressing End three times, you scroll down with the mouse wheel all the way (or with the vertical scroll bar), you will get at the end “show 4 more comments” (that actually are no 4, but 17). But all the 17 are shown at once.