Its best to write big and atleast fill up one booklet.
Examiners get put off it its only a couple of pages long, even if it is small writing. Its easier for them to mark if writing is large also.
Better to keep the examiners happy I say :p
Basically, you just need to pick a particular image from the film ie Fran the ugly duckling and relate your extra material to that, for example The Ugly Duckling fairytale.