It sounds like Melissa has used someone fairly well known as inspo for her speaking voice (outside of Pat Carroll). It's almost Thatcherish. Especially when she says "it's what I live for". My brain is 80% loaded in pinpointing it but I can't quite put my finger on it. Or is she just doing Gillian Anderson/Meryl doing Thatcher?
EDIT: Ok, she sounds identical to Myrtle Snow in AHS Coven.
EDIT: Ok, she sounds identical to Myrtle Snow in AHS Coven.