In Bridgerton season 1, Daphne’s disappearing necklace is one of the show's biggest plot holes, and it's a missed opportunity to explain Cressida's spying. Soon after Prince Friedrich gives Daphne the necklace in episode 3, “An Affair of Honor,” she discards the jewels on the garden bridge never to be seen or heard about again, but it could have easily been used to show how Cressida discovered that Simon and Daphne were together in the gardens. Instead, Cressida's spying and the missing necklace both remain a mystery throughout the series.
Cressida’s spying is an important element of the story because the rumor of their garden rendezvous is what ultimately pushes Daphne and Simon to make an appeal to Queen Charlotte, who plays a role in allowing them to move up their wedding date. It’s a great plot device for moving the narrative forward, but the confusion around what Cressida did or didn’t see, and if she actually started the garden gossip, is never properly addressed. It was unclear whether or not she had been spying on them the entire time, and, if so, why she had been in the garden in the first place.
Using the necklace plot hole to address these issues would have given more weight to the threat that ultimately leads Daphne and Simon to marry so quickly. This is important as the climax of Daphne and Simon’s story, the main storyline of the Bridgerton series so far. Before the incident on the bridge, it was obvious that Cressida noticed Daphne leaving the ball. Assuming Cressida followed Daphne and found the discarded necklace on the bridge, this could have led her right to Daphne and Simon in the garden. Showing this would have filled in important details of the plot that otherwise remain unaddressed.
Cressida could have even shown up in a later episode wearing the necklace, leaving viewers to speculate over how she ended up with it. One possible explanation could be that she stole it from the bridge while spying on Daphne and Simon. In another scenario, after Cressida retrieved the necklace and finished spying, she could have returned it to Prince Friedrich, putting herself in the good graces of both the Prince and Queen Charlotte. Leaving Daphne to explain her own carelessness to the Prince, along with the added anxiety of knowing that Cressida found the necklace in the garden, would have built more drama and heightened the tension between these characters during a pivotable moment in the story. Either scenario would have served the story well
It's unlikely that Bridgerton season 2 will go back and explain Cressida’s spying, but if the show wanted to have a bit of fun with the missing necklace it still could. Even something as simple as having the necklace reappear, say, hanging in Daphne’s wardrobe, could give viewers the satisfaction of knowing that it was eventually saved from the garden bridge.