I'm making no judgement either way. I'm not sure I get your explanation but what I'm saying is you can't divorce the history from the image just because your using it in another continent. I worked in a shop many years ago and we were printing some gicle's for an artist who had created some satirical pieces based on racist southern advertising (including the use of black face). The artist was African American and the art was intended to inform on racism. Some of the African Americans I worked with thought we should turn down the job despite it's intent and who the artist was. It's a tricky image to use without clear intent.
The black face is a pretty loaded image. this may be a French artist doing a poster for a show in Switzerland but the black face is a particularly American image (unless Europe had a tradition on minstrel shows -feel free to correct me). So you are drawing on that history and all it's baggage when you incorporate the black face.