As German requisitions took their lot of French productions, consumer goods were rationned and hard to obtain at the official rate to the point a noticable raise of mortality can be observed.
Black market develloped from this, holding consumption goods and selling them illegally at a higher price (for exemple, butter was 4 or 5 time more expensive). While develloping from a servile economic collaboration with Germany, it was largely villified as exploiting people in times of hardship, an accusation particularily used by Vichy Regime against war profiteers, often associated with Jews or people Vichy accused being responsible of the defeat in 1940.

This poster is well on the line of this official policy of denounciation ("A crime against community") while, like others, carefully avoided to point the huge respnsability of German plunder into its causes but as well its management (thanks to an inflated rate of occupation Mark, Germans wee privilegied buyers).
The denunciation was largely uneffective and while still socially stigmatized, black market was generalized by the time this poster was made, in 1943, and while Vichy still brand it as a crime akin to murder or deserving death penalty at least morally (hence the depiction of an hanging rope) it was more seen as a necessary evil which ended up representing between a tenth and a quarter of French food production.

Something changed in 1943, as German occupation authorities elected to use legal plundering of the french agricultural and industrial production, rather than using a more or less spontaneous black economy. Profiteers traficking with Nazis became part of a quasi-legal network (for exemple, the French Gestapo), and remaining sellers and trafickeers, still necessary to the broad maintenance of french consumption, were more and more seen (at least by themselves) as "resisting" German occupation by denying them goods while selling them to Frenchmen at a high profit. This went being supported by Resistance movements (which tried with more or less success, to regulate it and use it to supply themselves).

Basically, this poster was made to raise awarness on black market in France, at a point where it was less popularily stigmatized after having being consensually considered as innaceptable. Vichy more or less double-downed on this as German-driven black economy became quasi-legal both as a way to play on what was a popular theme in the first years of Occupation, while avoiding mentioning Nazi responsabilities.