At the beginning during the wedding scene, there is a woman with her right hand over her mouth behind the doctor as he says, "No....the undertaker. She's dead". As the shot changes to a wide angle, the woman has her left hand over her mouth.
When getting ready for bed, Pat unbuttons her jacket, but in the next shot the jacket is buttoned again and stays buttoned for the rest of the scene - because she changed her mind about going to bed.
Dr. Foster: These young girls, whether dead or alive, are being used by Lorenz in some manner as human guinea pigs to sustain his wife in a youthful state.