Roberts had been interviewing Humans of New York founder Brandon Stanton when he turned the camera on her.
Roberts opened up about her own struggles battling myelodysplastic syndrome (MDS), saying she did not anticipate the emotional and psychological toll the physical isolation would have.
The photo has received over 280,000 likes on Facebook and 160,000 likes on Instagram, with many users praising and showing their support for the GMA host.
"This may or may not have been the deepest thing I've ever read," wrote one Facebook user.
"You never know the strength you have until you have no choice but to find it. I wish you a lifetime of health and happiness," wrote another user.
Stanton's Humans of New York had exploded in popularity over the years with over 15 million followers on its various platforms. The photos and brief interviews capture an intimate portrait of people's lives as they walk through the streets of New York City.
See Roberts' full interview with Stanton on ABCNews.com.