On the front line of empire, colonials had been developing an increasingly aestheticised response to violence since at least the 1850s, when the Italian-British commercial photographer Felice Beato had set up his tripod and camera by a gallows and captured the hanging bodies of suspected Indian insurgents during the Indian “Mutiny” of 1857-58–thus creating what was probably the first ever photograph documenting casualties of war. (src)
The fruitless confusion over the publication history, use and circumstances of two pictures in Is the photograph "England’s Revenge in India" real, staged, or fake? left a loose end.
for which it gave its source as "Picture Post, June 3, 1939". Note the non-German date-format embedded within the picture.
The real source and more common name/title/caption is:
Felice Beato, Two Sepoys of the 31st Native Infantry Who Were Hanged at Lucknow, albumen print from collodion-on-glass negative, June 1858. The J. Paul Getty Museum, Los Angeles. Digital image courtesy of the Getty’s Open Content Program.
As there was a simple mixup that prompted the whole linked question, a search through the archive of Picture Post looked for the wrong picture and concludes in one answer that the (wrong!) picture is not in the archive.
The question now is: did the Picture Post publish this image, and on the date given in the propaganda book?
In this edition: Picture Post Vol 3 No 9 June 3 1939:
(Note that the Getty archive has this picture catalogued twice:
once titled as [Execution of Rebels, Lucknow] and once as [Retribution, Hanging Mutineers]. "Retribution" being quite closely related to the word "revenge" chosen in Raubstaat.)
The print magazine is archived online, but behind an unfriendly paywall. Some pictures from that publication are also available from Getty Images. There are of course a couple of alternative venues to get at that. Physical archives at a few libraries, private collections or perhaps some other online excerpts.
The title story for the respective issue is for example reproduced as a spread of the first two pages in Hila Cooper: "Reading Magazines: Stefan Lorant and Picture Post, 1939–1941: A Study Of The Picture Editor's Work from the Archive of Modern Conflict's Collection", Theses and dissertations, Paper 1304, 1-1-2012, p54. (PDF)