PDF is a Page layout format
The paste up can be done in any order and the page is still good in the end because the entire page was rendered, then displayed.
Other formats are mostly 'serial'. Top to bottom
With anything other than the most simple PDF, you get what happens next in the
markup, when you do a Calibre convert. Images can land where they are called, not in the place they were intended.
Another gotcha is Ligatures get the first part only ffi ends up f
The title you listed implies it will be rich in charts and diagrams
