If "!empty" on custom note field in Drupal Views, Global PHP field
Looks like the CiviCRM is adding a space '&amp;nbsp;' (may be because of CKEditor) into the custom table column , even though you leave it empty when adding/editing the record. 

You can see it if you do var_dump of the variable. See below screenshot



So the below logic should work in this case. 

&lt;?php
if ($row-&gt;id_info_for_display_33 !== '&amp;nbsp;'  &amp;&amp; !empty($row-&gt;id_info_for_display_33)) {
    print $row-&gt;display_name . ", " . $row-&gt;id_info_for_display_33;
}
else {
    print $row-&gt;display_name;
}
?&gt;


Give it a try.