What the hell did I just watch??? **spoilers**

This movie made no sense to me at all. I watched it because I was curious after seeing Robert Osborne's interview with Kim Novak on TCM.

It was billed as a suspense thriller surrounding the death of a famous movie star, and the young actress who was groomed to play her in a biopic. That much I get. But I was expecting some kind of big revelation at the end, such as Elsa would turn out to be Lylah's secret daughter or maybe younger sister. I can understand that Elsa may really have just been some random aspiring actress who happens to bear an uncanny resemblance to Lylah. Fine. But why did Elsa slip into those ridiculous personality and vocal changes? Before anybody says, well, she was so caught up in her role that she was taking on Lylah's persona, remember that Elsa launched into the German-accented tirade against Molly when she was first introduced publicly to the press, before she ever started filming the movie and playing Lylah. Also, when Elsa had her big confrontation with Lewis in her dressing room and started shouting in Lylah's voice about being pregnant at their wedding, how did Elsa know that Lylah had been pregnant? Rosella said she and Lewis were the only people who knew.

Granted, I was having a hard time hearing some of the dialogue and kept adjusting the sound on my TV, but did I miss some explanation of whether or not there was any connection between Elsa and Lylah, and what made Elsa pretty much "become" Lylah by the end?

Thanks to anyone who can clarify this for me!