Because a synopsis won't show the detail, like facial expression or emphasis on dialog, that an artist would need to draw the characters within the 'feel' and context of each scene. And that's what I need the artist to see. How to draw the characters, and how to frame the pictures so that they fit with the 'feel' of the scene, and the episode as a whole. Because that can have an impact on which angle the characters are drawn from, whether certain images should be close-ups or medium shots, etc. The artist has to draw all that, and make it 'fit' with the voice acting. To my understanding, seeing the fully-scripted episodes would be the best way to do that.