Definition of OT in IR: Two trains running on same track (back to back) and the train ahead is made to stop on loop so that train behind can be given way ahead of the looped train is official OT.
But here both the trains never take the same track right from the diversion point (towards NZM and GZB) and neither they are parked at same or adjacent PF's so calling it an overtake is a brutal insult to being called a Railfan.