VAL'S HOBBY TOYS

It's from book 6, chapter two; The Land of Shadow. I don't really get what it's describing here. I'm just reading it for fun but I like to understand everything and because it's above my reading level sometimes I get confused. Here's what I'm confused on:

Behind it (behind Mount Doom) there hung a vast shadow, ominous as a thunder-cloud, the veils of Barad-dur that was reared far away upon a long spur of the Ashen Mountains thrust down from the North. The Dark Power was deep in thought, and the Eye turned inward, pondering tidings of dought and danger: a bright sword, and a stern and kingly face it saw, and for a while it gave little thought to other things; and all its great stronghold, gate on gate, and twoer on tower, was wrapped in a brooding gloom.

What is being described? Also it says it sees a stern and kingly face, they don't mean Aragorn's sword and face right? Because at this time he is still in Minas Tirith, they aren't at the Black Gate yet.