Well I'm not a pilot so can't answer your question, but I'm guessing the photo's there to show what appears to be more contrail and so more thrust, and the illusion of the contrails being perhaps blown by a crosswind as they appear to be not directly behind the direction of flight.
Well... if so, the contrails appear to be blowing right to left. The larger contrail seems to come from the aircraft's left engine, ie the one on the right of the picture. More thrust would be needed from the aircraft's right engine though, if it was doing as you suggest... so think its just an optical illusion.
However... it's still a very good question for any pilots out there?