The policy has drawn criticism from all over the world.
The image was taken from a Getty photo of a two-year-old migrant girl who cried while her mother was being detained by USA border patrol officials near McAllen, Texas.
The cover reads, "Welcome to America".
"This is the case for my daughter, but it is not the case for 2,000 children that were separated from their parents", Valera said.
Moore, who has been photographing the American migrant crisis for more than a decade, was tagging along with United States border patrol agents who were waiting for a group of Honduran migrants to cross the border. "The little girl immediately started crying", the photographer told NPR.More news: Supreme court rules states can collect sales tax from online retailers
A Time story recounting the photographer's experience initially stated the girl was carried away screaming by border agents, and later corrected the article to say that was incorrect and that the two were actually taken away together.
While the separation policy has officially been rolled back, how and when the government plans to reunite those children with their parents is unclear. "This one was tough for me", said the photog, who regularly photographs immigrants crossing the border.
In April, the Trump administration announced a "zero tolerance" policy for illegal crossings, saying that any asylum attempt that is not made at an appropriate port of entry will be deemed illegal and the person will be prosecuted even if they have no criminal history.
"As soon as it was over, they were put into a van", he told the magazine. "All I wanted to do was pick her up, but I couldn't". "As the border patrol took peoples' names down, I could see a mother holding a young child", Moore said on Weekend Edition Sunday to Lulu Garcia-Navarro.
Mr Trump backed down from the policy on Wednesday after signing an executive order to stop families being separated.