The PDF could benefit from a revision. On one hand it's beautiful, nice layout, gorgeous art. On the other hand… no author attribution, no date, no artwork credits, not TOC, no bookmarks (NO BOOKMARKS!! Adding bookmarks is trivial and should be mandatory for any PDF longer than 4 pages). There are also several instances of "it's" that should be spelled "its". The "Video Explanation" paragraph is also weird and incomplete.