This leaflet shows a picture pretending to be published by the German police in order to identify bomb-raid victims.
Black propaganda is always trying to mislead the target in pretending the leaflet to come from a source in the targets own country. In this case it is the German police.
The allied maker added one word:
'Schluss!' (Stop it!)to urge the German people to put an end to the war and in that way also stop the airraids on their cities.
The most famous maker/designer of this kind of propaganda in WWII at the allied side was Sefton Delmer in England. He, and his (often German) staff, made most of the leaflets in this slide show.
The type of leaflets ranges from fake 'Feldpostkarten' (with even fake German postage stamps), to 'wanted' police pictures, forged ration cards, camouflaged malingering instructions, sabotage instructions and lots of small sticker type leaflets.
Sometimes a leaflet even pretends to come from a non-existing anti-nazi group from within Germany. If the maker is giving the target the possibility to see (or understand) that it is an allied leaflet (eg by giving one or two sentences that say so), the propaganda is called 'grey' instead of 'black'.