The striking image taken by Joyce at the height of the COVID-19 crisis earlier this yar, showed her colleagues writing their names, smiley faces and love hearts on their disposable PPE aprons.
The Duchess said: "Thank you so much for the image. It had such an impact it captured the moment, it was a look behind the scenes. The story of what you experienced is so important."
The Duke added: "It is important for history purposes to show that actually happened."
Joyce, who shielded patients on the hospital's cancer ward, said after her meeting with the royals: "I married photography and care together. I took a series of photos of them getting into and out of their PPE. I thought it was the most interesting aspect.
"It shows Amelia and Dipal writing their names with a marker on each other's PPE because when a patient wakes up, they know our names. It was a very touching sentiment.
"Patients were often in a coma and so coming round confused and didn't know who was treating them. But also we couldn't even recognise each other at times without names."
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