Other mistake: In Sarah's room, after the close-ups of Lancelot's empty shelf space and of Sarah beginning to say, "Someone..." as she finishes, "..has been in my room again," in this wide shot, while still on her bed until she leaves her room, there is a mark across Sarah's forehead that extends to the left side her eye. It isn't in the previous or following shots. (00:06:40)
Other mistake: When Sarah is in the room with the old hag who lives at the rubbish dump, the old hag asks, "What's the matter, dearie? Don't you like your toys?" Connelly is mouthing the hag's lines, presumably as a prompt to recall her own lines. (01:10:45)
Other mistake: When Sarah is at the end doing her speech with David Bowie in that upside down world and is meant to recite the speech word for word, she forgets the line "To take back the child that you have stolen" Instead she skips right over the line and says, " I have fought my way here to the castle beyond the goblin city - - missed line - - for my will is as strong as yours...etc. Etc."
Other mistake: As the cannon the Goblin army brings rolls to a stop, the smoke jet used to simulate shots is visible.
Other mistake: As Sarah looks at the opening that she can't readily see, the vine on the right side goes from sharp to blurry at the top of it.
Answer: They are real. This is seen when Jareth turns into an owl and Sarah sees him fly out of the house. Further proof of this is when everybody that Sarah met were in her room and Jareth was looking into her room before flying off.