Did you try it to see if/how it works?

FWIW, to answer the question, you'd have to ask the authors --- anyway, lexical vars are what its all about

sub itref {  \*STDOUT }
sub itglob { *STDOUT }
for my $it( itref(), itglob() ){
    print $it qq{$it\n};
}
__END__
GLOB(0x99b30c)
*main::STDOUT
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