Eagle-eyed viewers also noticed that the nun was wearing black Reebok Classics trainers underneath her traditional outfit, the Daily Mail reports.
Sister Annaliese Brogden was photographed sitting next to Prince William and his bride Kate Middleton, now known as the Duke and Duchess of Cambridge, wearing a pair of comfortable trainers, AEDT adds.
The internet was awash with rumours of Sister Annalieseâ€™s role at Fridayâ€™s ceremony, with some musing she may be an MI5 agent tasked with protecting the royal heir and dubbing her the â€œNinja Nun.â€
But the truth is more straightforward, according to her father, Geoffrey Brogden.
â€œShe wore the trainers for comfort and always has,â€ he said. â€œIt has all caused great amusement here and at the convent. In fact, I was more shocked to see the Prime Ministerâ€™s wife not wearing a hat.â€