Symbolism, Imagery, Allegory
The Seven Kingdoms hasn't yet invented La-Z-Boy technology. This is very clear when we look at the king, the most powerful person in the Seven Kingdoms, and his seat: the Iron Throne. The Iron Throne is made of the swords of defeated enemies. It was made centuries ago, when Aegon Targaryen conquered the continent with just his confidence and three fire-breathing dragons; but even so, the swords in the Iron Throne are still pretty sharp (44 Eddard 11.21).
This is one of those symbols (like house sigils and mottoes) that actually has meaning within the book. As Eddard remembers when he's sitting on the throne, "A king should never sit easy, Aegon the Conqueror had said, when he commanded his armorers to forge a great seat from the swords laid down by his enemies" (44 Eddard 11.2). In other words, the Iron Throne is a reminder (both to us and to the characters in the book) that powerful people can't afford to become lazy and comfortable.
Or, how about this? Is the Iron Throne also a reminder that the enemies of the past can still hurt? This seems to be just the situation that the Seven Kingdoms face. (But which enemy of the past is really dangerous: Daenerys, the exiled princess? Or the Others?)