The following gets at the content of images displayed on a page:

#!perl
use strict;
use warnings;
use 5.012;
use WWW::Mechanize::Chrome;

use Log::Log4perl ':easy';

Log::Log4perl->easy_init($TRACE);


use File::Temp 'tempdir';
use Cwd;
my $tempdir = tempdir();
my $mech = WWW::Mechanize::Chrome->new(
    headless => 1,
    data_directory => $tempdir,
    download_directory => cwd(),
);

use Data::Dumper;

my $res = $mech->get('https://egp.rutgers.edu/cgi/wmc.pl');
say Dumper $mech->getResourceTree_future()->get;

my $link = $mech->xpath( '//a[text()="MY IMAGE"]', single => 1  );
$mech->click($link);
$mech->sleep(1);

my $resources = $mech->getResourceTree_future()->get;
my @images = grep { $_->{type} eq 'Image' } @{$resources->{resources}}
+;

my $image = $mech->getResourceContent_future( $images[0]->{url} )->get
+->{content};

open my $fh, '>:raw', 'test.jpg';
print $fh $image;
[download]

Note that you will need a way to find which image is the one you want.