As Robert is getting on the elevator, he is carrying flowers wrapped in cellphone and white tissue paper. The flowers are visible and are pink, yellow, & white flowers. But when Robert hands Marion the bouquet in the apartment, they are unwrapped and the cellophane is gone, and they only contain red flowers.
In the bedroom scene when Marion throws a bucket of water over Nicky Henson and Geraldine Sherman, Geraldine Sherman from 43:08 to 44:31 shows her breasts and buttocks. Essentially naked as she leaves the bedroom, however when she opens the door into the next bedroom and then walks through the doorway, she is suddenly wearing white panties.
Near the end of the film, after Andrew leaves and Robert is sitting on the couch alone, the key light on his face quickly fades out - a technique seen in stage plays, but rarely in a feature film.