Those diagrms come from here: http://scotthurff.com/posts/how-to-design-for-thumbs-in-the-era-of-huge-screens http://scotthurff.com/posts/how-to-design-for-thu

Those diagrms come from here: http://scotthurff.com/posts/how-to-design-for-thumbs-in-the-era-of-huge-screens http://scotthurff.com/posts/how-to-design-for-thumbs-in-the-... though even there I cannot find any explanation for "ow-space". Maybe a reference to some game?