What kind of message would an object have that more clearly states what’s going on? Think of a shadow as a graphic expression.
Here's a link to some videos (some of which we looked at in class) that Tom Woodward shared with the spring DS106 class -- great examples of the variety of work done in digital video these days.
Here's a link to the audio of Tom's presentation about the videos mentioned in the site above.
Here's a link to Andy Rush's presentation to the spring DS106 class (similar to what you'll be seeing in class).