How is a portable cloud different than a package containing multiple files?
“Portable clouds” is a name for the idea that the “cloud” of the Internet is / can be made portable by copying portions of it onto your local networks, desktops and portable devices. Another way to say this is: really great replication and caching of the web.
On the one hand you have web pages that can easily move from host to host and URL to URL, like single page applications. Apps that use local storage (a feature of HTML5) rather than databases, for example.
On the other hand you have containers with multiple files in them, like the epub format for ebooks. Epub is a zip file whose contents are structured according to an industry standard. The contents are mainly HTML.
They’re evolving into the same place, or maybe they’re two different technology lineages competing for the same niche.
See also CMX.