• Image of Katharine Hepburn and Humphrey Bogart during the production of The African Queen.
• The photograph was taken on-set by the studio, most likely for publicity purposes. Such images were then disseminated to the media and the public to promote the film (see Film still).
• It is definitely not a screenshot as an exact image like this never appears in the film, and the quality of screenshots from the film are lower (see two here and here, for comparison).

Public domain explanation

• The image is reproduced on the Encyclopedia Britannica website, with the credit "Courtesy of United Artists Corporation". It does not include a © symbol, which EB does for images which are copyrighted. This suggests that the image here was either never copyrighted, or the copyright was not renewed.
• Since the image was published prior to 1977, under the terms of the 1909 Copyright Act (which was law until 1978), any copyright that may have been secured for the photograph would have had to be renewed 28 years after publication.
• The copyright for this image would therefore have had to be renewed in 1979. A search with The United States Copyright Office for "The African Queen" finds no trace that this occurred. Searching for "Katharine Hepburn" and Humphrey Bogart" finds no evidence that a photograph taken of them in 1951 had its copyright renewed.

Film industry author Gerald Mast has written:

"According to the old copyright act, such production stills were not automatically copyrighted as part of the film and required separate copyrights as photographic stills ... Most studios have never bothered to copyright these stills because they were happy to see them pass into the public domain, to be used by as many people in as many publications as possible." (Film Study and the Copyright Law (1989) p. 87.)