A text should be composed so that readers with limited vision, hearing, or touch-among other possible differences within an audience-can still interact with the text. For instance, imagine that you're filming someone who speaks American Sign Language-would you film the person from the shoulders up, cutting their hands from the shot? No!
No living individual is born the same. We all have different characteristics that make us who we are. The great thing about multimodality is that it targets different senses and needs that allows every individual to gain access to a certain topic but through different forms.