If they're going to play 6 songs off of High N' Dry, Mirror Mirror should definitely be one of them.
That being said I'd actually go see them after seeing that set. Would be cool to see Me & My Wine, Rock Brigade or Wasted since they're trying to please some of us pre-pyromania fans.
I give them credit for making the effort though. I had zero interest in ever seeing Def Leppard again before seeing this.