That looks really neat! It looks like a good way to try multiple versions of the same scene without having to draw and erase and re-draw stuff.
I plan all of my storyboards on paper, drawing the layouts for each page in thumbnail-size, which means I can't get too detailed on the art, but instead have to focus on stuff like panel-sizes, layouts, where the speechbubbles go, and the flow of the action across the page.
(Example from a short comic I made last year)
And these really are thumbnail-sized - they're two inches tall at most. As a result, the drawings sometimes get REALLY scribbly, so I have to write little notes to myself about what's actually in the panels - also, I write the dialogue at the same time that I draw the storyboards (before that, I'm working only from outline notes, no dialogue), so that ends up below the thumbnails as well.
Drawing a whole bunch of layout-thumbnails on the same sheet of paper helps me keep a good overview of the story, too. It's like a pen-and-paper version of Manga Studio's Story-function!
