Corrin said that, while attending a matinee performance, Princess Margaret actor Bonham Carter was approached by many fans – but Corrin failed to be recognised by a single person.
"I went to the theatre with Helena Bonham Carter and so many people came up to her and tapped her on the shoulder to say how much they loved her work," she said, adding: "And of course nobody knew who I was."
Corrin then revealed an embarrassing encounter she had at another theatre later that day.
"I then went to the theatre that evening with a friend and a person tapped me on the shoulder. I thought, ‘Oh my God, this is my moment.'
"But she had only come over to tell me I had a label coming out of my jumper. It was so bad!"
The pair appeared on a socially distanced taping of the BBC chat show that also saw Nicole Kidman participate via video chat to discuss her role in The Undoing.
Kylie Minogue and Strictly contestant Nicola Adams also appeared.
The Crown season four will be available to stream on Netflix from 15 November.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies