Is the Palace of the Dragon King a jutsu or a space dimension

king dragon jituMany jutsus in Naruto series that shaped like a vicious, mythical beast of a legend, dragon. It has been proven from our talks that have reached the third part. What dragon-shaped jutsus thatp>In the latest episode 53, Urashiki time freezes Toneri by saying that Enjoy the Palace of the Dragon King for the next 10000 years. So is it like Toneri is trapped in that