The click packages are very similar to Androids apks.
BYOD - Bring Your Own Dependencies
Sandboxed - Declare what you want to use and let the user allow or deny.
Not possible to access anything outside your sandbox if not
No install scripts - Your app can't do anything until the user chooses to start it.
explicitly specified in the manifest.
It's simply a easier package that is safer (sandboxing, install scripts) and suits
better in the phone where users tend to install everything they can.
For desktop sand boxing is of course nice, however BYOD may be a pain in the ass.
Personally I think they should delay the 1.0 (13.10) release to 14.04. It isn't
done and Mir won't be tested enough. If they want they could release but
tag it beta, preview or something like that...