It is known who copied and possibly also took this photograph in 1940 in Warsaw. |
Alamy: Orphans of Janusz Korczak orphanage preparing food at the courtyard in Krochmalna Street In Warsaw, Poland (ca. 1930's). Captions are provided by our contributors.
So, there are for example people who take others' photographs and "contribute" with them to Alamy.
"Others' photographs" mean pictures taken by other photographers.
What is special, is that many museums and editorial offices do buy these photos or licences from Alamy and other distributors that do not have the rights - copyright!
So, numerous people sell actually the copyright that does not belong to them or photos without the copyright.
When you sell your images through a stock photo site, you retain the copyright. However, you are offering the images with a royalty-free license, meaning the person who buys it has certain rights to use it. They might use it for marketing materials, such as on their website or on a brochure. However, they cannot resell your photo.