Continuity mistake: When Velma presents a new mop to Two-Mop Maggie turning her back into Three-Mop Maggie, the ribbon in close-up has the two longer bits across the handle, which becomes just one in the other shots. (01:10:15)
Other mistake: Nothing about Nedley Blake's interference in his daughter's morning routine at home makes remotely sense the way it is shown. It takes him 18 seconds (with cuts) to do something that needed to be made in the 6 seconds it originally takes Daphne to come down the stairs, and the first time around he was also shown arriving from the kitchen, which would further expand the time needed (considering also that the second time he apparently dropped the tray, causing rattling noise that Daphne should have heard). Not only that; the playlist action (which is something her computer science mother could have easily done with actual software, especially given the level of tech available to every teen in the movie) takes twice as long too, and at the end of it he exits the frame from the wrong direction - he should have headed left, because he needed to get into the closet to pass Daphne the proper clothing posing as the automated wardrobe.
Other mistake: Velma tries to "override the system" to free Mikayla; the screen fills with the typical pseudo-hacker gibberish from the Hackertyper app, and she asks Daphne to tell her the serial number; Daphne reads just the first part of it and leaves out the rest.
