The problem is that I can open the image on a webpage, but all the body text vanishes. Looking in the source of the webpage, you can still see the body.

This is obvious since the following:

    print $q->header(-type => 'image/png');

    open IMAGE, $image or die "Cannot open $image $!\n";
    binmode STDOUT;
    print <IMAGE>;
    close IMAGE;
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Will print the appropriate header and send the data constituting the image, which is the reason why you will actually see it in a browser. And that code is called by

    my $get_image = thumbs::get_thumbs($client_id);
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in your main.pm.

I think you just want in your main.pm to print a src attribute set to an url that will actually call thumbs.pm.