The photograph, on its face, is unexceptional. Taken on Monday, it shows several older women, smiling alongside staff in a sitting room at Laurel Court, a nursing centre in Alvin, Texas.

What makes it significant is its contrast with an alarming, surreal photograph taken just one day earlier.

That one showed several of the same women -- and a black-and-white cat -- inside La Vita Bella, a single-story assisted-living facility in Dickinson, Texas. The women were waist-deep in murky floodwater. They appeared to be waiting calmly for assistance as heavy rains continued outside.

All the residents were rescued by emergency responders on Sunday afternoon, and most had been moved to Laurel Court by Sunday night. The two facilities are about 16 kilometres apart.

"They're all resting comfortably and safe and sound," said Rick Van Warner, a spokesman for Cantex Continuing Care Network, of which Laurel Court is a part.

The successful move was one bright spot in what has been -- and remains -- a harrowing week for Houston and surrounding areas in the aftermath of Hurricane Harvey.

The women rose to national attention on Sunday when a Florida resident, Timothy McIntosh, posted the photo of them amid the rising water inside the single-story La Vita Bella. In a phone interview Tuesday, he said his mother-in-law, Trudy Lampson, owned the facility and had sent the photo.

"Her cellphone was about to die, and that was the last communication,'' he said. "That's the last we heard. We were frantic, so the first thing I did was just call every emergency department in Houston and all over."

He shared the image on Twitter as well, hoping to alert people in Dickinson. The post was shared online thousands of times. Some expressed outrage. Others tagged emergency responders. Still others insisted the image could not be real.

McIntosh said he was frustrated that so many doubted the image or questioned the management of the centre. He said Lampson, who could not be reached for comment, had an evacuation plan in place but was advised by officials to stay put.

After making several calls from Florida, McIntosh said, Ken Clark, a Galveston County commissioner, answered the phone at the county's office of emergency management.

"They were fantastic," McIntosh said of the emergency workers, who kept him updated throughout the day until the La Vita Bella residents were rescued.

Clark confirmed in a phone interview Sunday that the residents had been evacuated, though he could not say for sure how many.

An emailed statement from Laurel Court said that nine of the patients evacuated from La Vita Bella had arrived at Laurel Court by Sunday night. "We were able to provide these patients with hot showers, food, warm beds, and a safe haven," it said. Van Warner said in an email that one more patient arrived Monday.

The Daily News, a Galveston County newspaper, reported Sunday that 18 people were rescued from the centre in Dickinson. It remains unclear how many of those were staff members, and whether any La Vita Bella residents are still receiving medical care elsewhere.

McIntosh attributed much of the success of Sunday's evacuation to Lampson, calling her a "guardian angel" for keeping the residents of La Vita Bella calm as the floodwaters rose.

And Tuesday, he updated his Twitter feed with a photograph of one more resident who survived the storm. Bozo, the black-and-white cat who was perched over rising waters in La Vita Bella on Sunday, appears to be doing just fine.