Corrected entry: In the scene when the Grand High Witch first steps on the stage in the convention room, her dress is shown as tight-fitted and far above her knee. After she reveals her true face, her dress is shown as loose and far below her knee. When she puts her mask back on, her dress is again fitted and above her knee.
Corrected entry: If the witch's secretary could change Luke back into a human, how come the Grand High Witch, the most powerful witch, had no such power to transform herself or the other witches back into their original forms as they were turning into mice? In fact, they never explain why the secretary had such miraculous powers.
Corrected entry: When Luke asks his grandmother if she had ever seen the Grand High Witch, she replies that nobody ever has. Later, in the film, at the hotel Helga sees the Grand High Witch and says there's something familiar about her. Plus, when the witches are turning into mice, Helga points to the Grand High Witch. Since Helga never saw her before, there's no way she should know exactly which of the witches was really the Grand High Witch.