Is there a difference when installing plugin from zip file or from enterprise respository?

Is there anything different behind the scenes on how IntelliJ handles installation of plugin from a zip file or from an enterprise repository?

I'm noticing a difference in behavior in particular with this piece of code...

getClass().getClassLoader().getResource("library/somefolder).toURI().toURL()

"library/somefolder" is inside the plugin jar file.

When installing from a zip file, this returns a valid resource.

When installing from an enterprise repository, this results into a NullPointerException.