Duchess Catherine is well-versed in the art of making subtle outfit tweaks without a soul noticing, but her latest twist might just be her sneakiest yet.
The mum-of-three stepped out with husband Prince William on Tuesday evening wearing a heavenly Eponine dress for a night out at the theatre.
And while the world looked to her gorgeous sparkly heels and handbag, there was another embellishment to her outfit our eyes didn't quite catch at the time.
A blogger known as Kate's Closet pointed out the small tweak to fans, noting that the royal had swapped the original buttons from the dress, which originally featured little crowns, for larger, diamante buttons.
Now that's an eagle-eye if we ever saw one!
The beautiful dress design was nothing short of heavenly - and the inside of it was just as stunning as the outside.
Jet Shenkman, who is the creative director behind the label, spoke to PEOPLE about its creation, telling the publication: "I think a dress needs to be as luxurious inside as it is on the outside – and hers featured a lovely cow parsley print, just in bloom."
And while Kate's dress certainly had a clear royal theme with the crown button detailing, it's undeniable that the design was regal enough in its own right.
There's no denying those sparkly buttons set it off perfectly!
The dress wasn't the only thing that got people talking that evening.
Shortly after they attended the performance of Dear Evan Hansen, the Duke and Duchess' official Instagram account, Kensington Royal, shared a sweet behind the scenes video, which featured a rare insight of the royals interacting with guests - and each other.
At the end of the short clip, Kate is seen looking at Prince William with a giant grin on her face - something that caught the eyes of fans, who commented on the sweet interaction.
"That second of the Duchess smiling ❤️❤️," a fan wrote.
We can't blame them, the evening provided us with plenty to talk about.
We can't wait for their next evening soiree!
WATCH: Kensington Palace share rare behind the scenes video of Kate and Wills' night at the theatre.