When Laura enters her studio above the empty warehouse, she is wearing red high-heeled shoes. When she runs in terror through the warehouse, she is wearing sneakers, but immediately afterwards, she is once again wearing the high-heeled shoes.
Someone sort of mentioned this, but they got her footwear wrong . When she is running through the warehouse in dear for her life , she was Not wearing Tennis Shoes. she was wearing Brown Printed Fabric Quilted Ankle-Booties.
When the killer kicks in the metallic door to Laura's bedroom, dents/footprints in the door from previous takes of this shot are visible.
During the catfight/car-burning photo shoot in Columbus Circle, Michele motions to Lulu (Darlanne Fluegel) to not pull her hair so hard and says, "God, Darlanne! You don't have to pull it that hard!" [Note: the word "Darlanne" is nearly unintelligible, if it is, indeed, even the word that is spoken.]
When Laura sees an especially frightening vision, the camera cuts to her eyes in closeup. Her pupils are not maximally dilated as they would normally be by extreme emotion, but are pinpoints. This likely would have been a technical difficulty as the bright lights in the C/U would shrink her pupils.
When Laura is demonstrating to John Nevlle with the video camera, crew members are reflected on the monitor/TV screen.
When the staged car wreck for the photo shoot is being set up, the camera, camera crew, and boom operator all can be seen in the chrome bumper of the car that is rolled over.