Without the specific political cartoon to view, I can only infer based on the context of the Plessy v. Ferguson ruling. The Supreme Court decision upheld the constitutionality of racial segregation under the "separate but equal" doctrine. If the cartoon critiques or highlights the negative consequences of this ruling, it might suggest that "Separate accommodations are not acceptable."
This aligns with the broader historical criticism of the ruling as it validated discriminatory practices and reinforced Jim Crow laws, leading to significant social and legal inequalities. If this resonates with the message in the cartoon you have, then that would be the most fitting interpretation.