During the scene when Miriam offers the drink to Sarah, Sarah is standing in front of a bust depicting Miriam. The camera pans between the two a total of three times. The third time, when Sarah takes a sip of her drink, the bust is not there.
During the quick cuts when John attacks Alice, blood splashes on the sheet music. A few cuts later, the music stand is kicked to the floor, and the open pages are now blood-free. The unstained pages are seen again at the end of the sequence (in a fade effect that reinstates their blood stains).