After the script is complete, we have a "storyboard launch" meeting. I talk with the director (in this case it was WB veteran ~samliu
and the storyboard artists about key story points, important emotional beats we wanna hit, etc. These thumbnails help quickly communicate ideas I've been kicking around in my brain ever since we started the writing process.
What's cool is that despite being small and rough, these thumbs very much convey final shots from the show!