The ship is more or less beeing built from fore to aft, but the first segment (= front) is still missing. She is definatly beeing built differently to the existing ships, because the Meyer Shipyard can built one full ship + a 3rd of a ship in one hall at the same time.
More or less all decks of the first 3 fire zones of the Dream where fully in place by end of December. As the "Celebrity Eclipse" has left the dock in early March, the yard now has the space to finalize the missing sections of the Dream. As soon as steel work for the Dream is done, she will move backwards close to the big gate and work on the next Celebrity ship will start in void the space in front of the Dream by then.
It's hard to see on the webcam picture, but the steel work for the entirty of the lowest deck of the dream is mostly done.