Take a good look at the image above. That's the cannon disk section of the Deathstar. This brings so many questions:
J. J. Abrams is definitely applying the same formula used for The force Awakens, and that's using as much of the familiar visual elements from the original trilogy as possible. so bringing our heroes and villains to the place where the Empire was defeated is like bringing the saga full circle to him. or maybe it is just that, a visual element to gives us a sense of nostalgia and connection between trilogies.