Sophie, the Duchess of Edinburgh is starring in a new portrait for her 60th birthday, and the photographer behind the camera is sharing an unseen snap from the photo session.

In a series of candid photographs by Christina Ebenezer, the Duchess of Edinburgh chose a wardrobe of re-wears that hint at her new era of royal life

Sophie, the Duchess of Edinburgh is marking a milestone birthday! She turned 60 on Jan. 20, and friends and former colleagues have been honoring her contribution to the royal family – amid the release of the duchess' stunning new portrait.

The duchess is set to celebrate the milestone at home with the Duke of Edinburgh on Monday at her Bagshot Park home.

A photograph of the Duchess of Edinburgh smiling has been released by Buckingham Palace to celebrate her upcoming 60th birthday. The photo of Sophie mid-laugh perched on a window seat at her home in Bagshot Park was captured by the London-based photographer Christina Ebenezer earlier this month.

I love how she is not afraid to try new things and she makes beautiful choices,” designer Suzannah Crabb of royal favorite Suzannah London tells PEOPLE