Princess Eugenie is noticeably slimmer months ahead of her royal wedding to fiancé Jack Brooksbank.

On Thursday, the next royal bride stepped out in a see-through dress with a black obi-style belt, which she paired with pointed thigh high boots, in London's Carnaby for the launch of Pass on Plastic project. Princess Eugenie accessorized with a pair of classic gold drop earrings. Based on the photos, her weight loss is apparent with her slimmer figure.

The event that Princess Eugenie just attended was a joint campaign from Project O and Sky Ocean Rescue. It aimed to reduce the use of disposable plastic water bottles.

Last week, Princess Eugenie attended the garden party at Buckingham Palace with Queen Elizabeth II and Prince William. The royal surprised everyone with her eccentric hat from Misharada with the word "love" printed on it in silver beads.

Princess Eugenie is popular for her unique and bold fashion. In fact, many designers believe that her wedding dress will be contemporary.

"Princess Eugenie has shown us all over the last few years that she knows her own sense of fashion and is not afraid of colour and bold shapes even though she does tend to stick to knee length or over the knee hemlines," Kate Beavis, fashion expert from Magpie Wedding, told Express.

"I think we will see something more contemporary and fashion-forward than Kate and Meghan's dress choices and I'd imagine this will carry forward to the bridesmaids too and how she chooses to style her besties," Beavis added.

Meanwhile, Cambridge Vintage Bridal's Siobhan Mulholland believes that despite Princess Eugenie's different taste in fashion, her wedding dress will likely give a nod to her mom, Sarah Ferguson.

"We very rarely see her in floor-skimming dresses or even trousers because she works the A-line knee/shin-skimmer dresses so well," Mulholland told Express. "If ever someone had the opportunity to up-cycle and restructure an iconic 1980s wedding dress, it's Eugenie!"

Princess Eugenie and Brooksbank are tying the knot on Oct. 12 at St. George's Chapel at Windsor Castle where Prince Harry and Meghan Markle also exchanged "I do's" in May. The couple's royal wedding is expected to reflect some of the elements from the Duke and Duchess of Sussex's nuptials.