GLOB variables can't be serialised by Storable because it is a pointer to a table that is part of the current Perl runtime. If it was saved and restored, the symbol table in memory would not be the same one and it would not be able to point to the same entry. (Did that even make sense?! I hope so, it's a little tricky to explain).

The question here, though, is why CGI's param method is returning a typeglob. Possibly the method performs differently in a string context?

I notice that the form variable you are referencing is called pic1 - is the form a multipart file upload form? If so it makes more sense since CGI is probably giving you a filehandle to an open file that you will then have to do something with (like reading it into memory, copying it to a file etc.).