GREAT-Very Understandable and Entertaining.
I don't know if you were soliciting comments. My excuse:I am only a very old engineer.
I guess you were aiming for a maximum time. The ONLY suggestion I have is: To slow down a bit explaining the parts of the ePUB "book".
I especially like the way you used pieces of colored paper to explain each part. Much better than watching PowerPoint slides. Sorry I am not up to date on the technology you explained so I can't say anything about the facts you presented.