I need to create an ad for my multimedia class and it needs an idiom and it has to make sense in both figurative and literal meaning?
You should use a simple idiom that is easily memorable. It should create a visual appearance of what the multimedia class is about without necessarily including it. You can find ideas from http://grammar.yourdictionary.com/style-and-usage/Figurative-Language.html.
then find one and make it with your handy little brain, human