Different Warnings when compiling each Elisp with a single Emacs process?

[Bastien]

Hi,

I'm trying to understand what compilation warnings are shown when
several files are compiled within the same Emacs process and when
the same set of files is compiled with one Emacs process per file.

Let's assume this is with emacs -batch -Q.

My assumption is that compiling a file does not load it.  So I 
don't really understand why there are different warnings.

Thanks for any hint!

-- 
 Bastien