In Episode 1 we see a whole sequence in the Red Room that culminates in Dale Cooper falling through the floor and going through glass box, the ultraviolet realm and ending up in the Dougie trap! 

In Episode 18 we see that sequence again. But it has changed. What are the changes and why:

Laura palmer is not in the seat. The evolution of the arm talks about the little girl who lives down the lane. The closed curtain is now open. Diane is waiting for Dale when he emerges. They both know they need to head to some power lines where everything might change. 

Is this the sequence from episode 1 retold as a result of changes in the timeline (Laura being 'saved') or is Cooper returning to the Lodge. I guess I'm asking "is it future or is it past?" The car Dale and Diane drive and the car Richard wakes up to would seem to be significant in determining this.