Continuity mistake: When Matilda is reading near the beginning and her father says she's four, after she's talked to her parents, she walks away, and she's facing the door when her mum says that there's something wrong with her. When Matilda is having flashbacks to help her use her powers, she is still stood there, facing into the mirror whilst her mum says that. (00:08:32 - 01:09:02)
HPenguin
14th Jan 2020