I was actually wondering about the dress code at that evening:
It is all over the place:
Queen Beatrix in full force with a tiara, Maxima just missing a tiara, WA and Pieter in tuxedos with orders on the lapels and then the guest of honour looking like on any given day at the office.
Did he get the wrong information? Was his suitcase with the tuxedo lost at Heathrow airport?
Did Maxima and Margriet in the very last second ripped off their tiaras to tone done the event a bit (with the amount of hairspray the Queens hairstyle is probably glued into place it seems impossible to pry out the tiara)
I cannot imagine that WA would have donned a tuxedo instead of a dark suit had he known his guest would prefer business attire...
BTW the orders are very small indeed, the Danes got bigger ones. Although a bigger one and QB's decollete would have revealed a golden heart and quite a bit of indecencies. This star goodie was pulling mightily and the neckline plunging deeply...