The majority of the board said the advertisement showed a real-life event that was widely reported would be familiar to most people.
While the image of the dead body was confronting, it was not gruesome and there was a high public interest, the board said.
The complainant appealed the decision because in their view the decision did not consider strongly enough that the poster had been used for advertising, placing too much emphasis on the value of the photograph itself.
"A line needs to be drawn between exhibiting a photo depicting terrible real life events and using that same photo for the advertisement that is available to a wide range of audience [including children]," they said.
In their appeal application, the complainant challenged the majority view of the board that the image would be widely known.
In their initial response, the World Press Exhibition pointed out the image had won World Press Photo of the Year and had been used to promote the exhibition in 100 cities and 45 countries around the world.
The poster carried a disclaimer saying viewer discretion was advised and care had been taken to ensure the posters were not put up near schools or kindergartens or in any other locations that could offend, the World press Exhibition said.
"At no point did it select this photo with any intent to promote indecency, offensiveness, violence or a disregard for safety."
The board considered all the matters afresh and agreed the use of such an image to promote an exhibition in a poster advertisement to an unrestricted audience did offend against generally prevailing community standards.
Accordingly, the appeal board ruled the complaint was upheld and the appeal was allowed.
