Holy shit, it's all clear to me now!
Actually, IE is about an actress's creative process and reaches some sort of enlightenment in the end, battling some demons along the "yellow brick road" and so forth. 8 1/2 (which Lynch claims as one of his favorites) deals with a filmmaker's creative process and also like Laura Dern, reaches the enlightenment - Guido looking out of the car window and Nikki looking at the shining light no longer flickering.
And following that, party time!
One of the things I love about IE is its ghostly tone, it really gets me thinking of it as a ghost story where ghosts meet in a dimension where there is no place, no time, etc. - the dimension called "enlightenment" perhaps.