An Observation about Norma

I have seen Norma a number of times in several productions from very conservative to WWII style.  There is one thing I have never seen.  Norma is a priestess who during the opera conducts two different religious ceremonies.  What usually changes when one transitions from normal life to a religious ceremony and back again?  One usually appears first in street clothes, followed by vestments, followed again by street clothes.  Have I ever seen Norma appear in what would appear to be a ceremonial garment of any kind?  No.  This is why the actions always feel wrong.  We need more than you telling us she is a priestess.  We need to see it, too.