See also Iron Throne
King Joffrey Baratheon has the room redecorated to be more imposing after taking the throne. Joffrey restores the throneroom back to what it used to look like under the Targaryens, replacing the decorative vine motifs with metal spikes and roaring fires surrounding the pillars. The tapestries of hunting scenes are removed. He does not replace the skulls of dragons which used to be placed in descending order by size in the throne room 
He does not replace the skulls of the dragons, which used to be placed in descending order by size. They decorated the room in the time of the Targaryen kings as told by Viserys to Doreah. 
The Iron Throne room is where the court gathers to hear the decree of Eddard as Hand of the King pronounce that Ser Gregor Cleganehas been stripped of lands and titles, because of his raids of the Riverlands.
Before Joffrey redecorated
After Joffrey redecorated