It turns out today was the annual Queen's parade around the Hague. From what I gather, today is the only day in the year that the Queen goes around the Hague and says hello to her constituents.
I blame the Dutch for being too tall for me to see anything. I was behind everyone, so I wasn't able to see past heads when the royal caravan passed by. Thanks to the unique location of our apartment, however, I was able to see someone who looked important while I was on my way to the grocery. See my mystery royal (in purple):
She looked rather young, so I'm thinking she's one of the Princesses married to one of the Queen's sons.
Lesson learned for today: I have no paparazzi skills.