The scene does come directly from JRRT's Frodo's encounter with Galadriel at the Mirror. The haughty Noldorian princess, related to but not controlled by Feanor, came to Middle Earth in the first place to set up her own kingdom and rule it to her pleasure--so that scene meant a lot when she suddenly became fragile, humbled and "diminished" after playing Lady Frankenstein. I think it works. "I'll remain Galadriel..."
I know the scene had to be there. I just think it was a bit over the top in the way it was done...
Heh... I think the visuals in the Galadriel Halloween scene were just a little over the top is all ;~D
I think it's easy to be too hard on the films for not showing something exactly like we pictured, or not showing the full depth of all the characters found in the books. We've certainly gone round and round about changes and omissions and additions to the plot. But after all that was over, it is a pretty good work of film.
I think it was, without exception, perfectly drawn in the films... the art and set were perfect. I also think it was perfectly cast, but some might disagree around the fringes.