The saying goes "dress for the job you want, not the job you have," and Kate Middleton apparently takes that to heart. The Duchess of Cambridge may not be Queen Kate just yet, but her formal Alexander McQueen outfit (plus, that tiara) last night could've fooled us.

Middleton wore one of her most regal looks yet, paired tastefully with a rare jewelry honor right from Queen Elizabeth's closet, and yes, it was a very big deal. While we gawked over her yellow pin and its significance — this is the first time in over a decade we've seen a new royal wear the honor — another detail of the piece slipped discretely under the radar. But fear not, because royal sleuths caught it.

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In addition to being Queen Elizabeth's Royal Family Order, Kate's brooch was reportedly made out of glass, rather than ivory like other pins. According to Majesty magazine, this change in materials was done intentionally as a vouch of support for Prince William's campaign to ban ivory.

"When I was born, there were one million elephants roaming Africa. By the time my daughter Charlotte was born last year [2015], the numbers of savannah elephants had crashed to just 350,000," William said in 2016, according to Elle UK.

"And at the current pace of illegal poaching, when Charlotte turns 25, the African elephant will be gone from the wild. My rejection of ivory today is not a judgment of past generations. It is an acceptance of the world as I find it today and the world I want my children, George and Charlotte, to inherit."

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Coupled with Princess Diana's Lover's Knot tiara, Middleton was wearing at least three tributes to her family in one look. Leave it to a royal to wear a stunning Alexander McQueen gown and have everyone talk about her jewelry instead.