What does "film cue" mean?
Solution 1:
I'm not sure I agree with your analysis.
"Cue" in the film or theatrical sense is as Michael says: "To give a signal - either a waved hand, a flashing light, a specific event (The knight getting his head chopped off...), or a verbal command from the Director or an actor for something specifically mentioned in the script to happen.
For example: "Order in the Rollerskating vicar!", as it appears towards the end of the Monty Python's Flying Circus Court Marshal Sketch.
This line in the script: "Order in the rollerskating vicar!" is the specific cue for the actor that is the vicar, who is waiting off-camera for his 'Cue', to enter the scene... As he does.
I think this demonstrates the meaning exactly. It's also a good use of 5-minutes of your time as this is a 'Classic' Python.