Loading…. a most frequently used part in flash movie. To avoid your user see a blank screen and don’t know what happens, you provide them with loading animation indicating the progress and how long your user will be able to see the movie.
Of course, flash authorizing tool provide its progress bar component which has been universally used. However, if you want your movie looks different from the other, you might need to offer your user a unique loading animation. I have seen a lots of creative design for those. But, the more complicated loading animation, the larger swf file, which might cost user waiting sometime until they can see the loading part. That will be worse when our user has slow internet experience.