header('Content-Type: image/jpeg');
$pics = file( $_GET['pic'] );
if ($pics != false) {
    for($i=0; $i < count($pics); $i++)
    {
        echo $pics[$i];
    }
} else {
    exit();
}

/* HTML
--------------------------------------------------------*/
<img width="300" src='vote_grab.php?pic=http://abc.com/abc.jpg' />