Among the things I've noticed is that metadata entries are included for both "comic" and "children" book-types, rather than one or the other. The "hybrid experience" mentioned in section 5.3.4 of the Guidelines does not state explicitly that both content types must be specified in order to create magnified text boxes in graphic novels, nor even that you can add both. Nor is the specific functionality of these two classifications anywhere clearly defined, but it is presumed the "comic" setting allows for image zoom, while "children" provides the text box magnification feature. However, a quick test in changing "children" to "comic" in my own KF8 version of The Ring Saga made no difference that I could ascertain, as text boxes still zoomed just the same.
Additionally, there are a few unique elements in the .opf's metadata section, most notably in two new zero reset functions:
<meta name="zero-gutter" content="true"/>Presumably these are designed to remove the default white space in the margins of the Kindle app, although their use is not included, nor explained, in the Publishing Guidelines, and I'm only guessing at the purpose of their inclusion. Certainly this is not required for fixed-layout content on the Fire.
<meta name="zero-margin" content="true"/>
There is also an enhanced doctype declaration in the html files:
SYSTEM "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"as well as the additional meta element:
meta http-equiv="Content-Type" content="text/html; charset=utf-8"Neither of these are present in the KF8 children's sample, but presumably they provide enhanced functionality not present in the 1999 standard but not yet finalized in HTML5.
Regardless, the sample provides much clearer examples as to how the Panel View region magnification functions, and how the larger resolution images can be used. The CSS in particular provides a wealth of information about how the mag regions are created and positioned, although at best it still seems an extremely tedious process of trial and error will be required to fine tune the zoomed image's location. Still, at least it's now possible to do, which is a start.