The iron throne is supposed to look a lot different than it does in the show. George R.R. Martin should know since he created the story, and he’s described in a way that’s quite grisly and not at all like the creation that was given over to GoT. While the one in the show does look intimidating it’s not nearly as accurate as it should be. The iron throne is supposed to be a monstrosity, a true testament to the rule of the Targaryen’s. It’s not realistic unfortunately and for the real throne you would need something the size of St. Paul’s Cathedral to really give rise to the real throne. The ruler that sits upon it should be a good ten feet off of the ground, and the ruler should have to walk up to sit upon an asymmetrical throne made of a thousand, melted swords that were taken from conquered foes. People are supposed to look upon this hideous thing and either tremble or feel the absolute pride in their ruler that they can sit upon such a thing.
That’s the difference between books and TV however. In the books there virtually no limits that rest within the story aside from those that the author assigns. Anything can happen in books so long as the writer is in control and deems it to be necessary. By creating a story you control how things are going to go and what is going to be normal. But in TV the restrictions on height and size are pretty much dictated by the size of the studio. They could possibly create the real iron throne through CGI, but it might not have the same effect. Plus, when you really think about it the iron throne is more of an ideal than the actual throne represents. Throughout the history of the show the idea of possessing the iron throne has become more of a desire than the actual need to sit upon the unholy thing.
George R.R. Martin has no doubt put a lot of thought into his stories but one thing that seems to vex some fans is that he throws a lot of his characters away so needlessly. That’s not entirely fair but it seems somewhat accurate since Ned Stark and several others seemed like they had more of a destiny in the story than they were really given. To the author it no doubt made sense to get rid of them since there is a delicate balance that has to be struck within any story, but to the fans it’s usually harder to accept since they don’t see the whole plan as the author does, nor will they fully understand it until everything is revealed. The trick of being an author is that other people don’t get to see inside your head unless you allow it. And even then, some people might not want to see what’s in there.
The iron throne is imposing in the books and in the show, but if we could have seen its true representation it might have been deemed far less desirable for its form than for its meaning.