Didn’t really get the gypsy reference, so I looked it up, Charlie directly answered to the emotion it caused here: https://charliehebdo.fr/2018/06/societe/ je-ne-suis-pas-charlie-halep / (the paywall can be bypassed with reading mode). Basically, they are saying that what they did is a satire of French people prejudices against Romanian people. They often do that, they reuse the words/prejudices of the people they criticize in a satirical setting to mock it, though without knowing Charlie’s culture, it’s difficult to interpret. Consider it as the equivalent of “/s” at the end of a comment here.
The framing is having it on Charlie Hebdo and knowing what is their style. When people take it out of this context and with no knowledge of local politics, it will easily look racist. The same happens with a satirical comment here, take it out of context and present it at a family dinner, it will not be received the same.
Let me take an up voted comment from here as an example.