I've never seen a syntax like $object->(list)

The variable is likely not a full object but just a simple coderef. eg:

#!/usr/bin/env perl
use strict;
use warnings;

my $code = sub { print "I found a $_!\n" for @_ };

$code->('x', 'y', 'z');
[download]

See Arrow Notation in perlref for more.