What does this Omega theme warning / notice mean?
The $pattern needs to be filled with one of the values to the right of the question mark. To find which value to use, Drupal checks the global variable $GLOBALS['language']-&gt;dir if it contains the value 'rtl'. If this is true, the first value is assigned, otherwise the second. Basically this is a short notation of if-else. 

The problem is, that $GLOBALS['language']-&gt;dir does not exist, so php throws an error. 

The lines part should read $GLOBALS['language']-&gt;directory
There seems to be a fix here, which is from 2014, so there is a good chance this fix was already integrated into production. 

You might be able to fix this issue by upgrading the Omega-Template to the latest stable or maybe development version (after creating backups!)