In this Thomas Nast political cartoon, the interactions between Sheriff Brennan, Boss Tweed, and the Shadow of Justice serve to convey a critique of the political corruption and its perception in the society of the time.
Sheriff Brennan's words and his lighthearted demeanor towards Boss Tweed suggest a complicity or an unwillingness to confront corruption seriously. By calling Tweed "my man" and jokingly acknowledging him, Brennan downplays the significance of Tweed's arrest, implying that the corrupt practices associated with Tweed are not being taken seriously by the authority that should be enforcing law and order.
On the other hand, the Shadow of Justice, stating "I will make some of you cry yet," suggests that justice, although overshadowed by the prevailing corruption and mockery, still holds the potential to eventually prevail. This figure indicates that true justice will come to those who are corrupt, even if it isn't immediately evident or acted upon.
Overall, the cartoon suggests a critique of the legal and political system's failure to hold corrupt individuals accountable, while also hinting at the idea that justice, although delayed, will eventually catch up to those who think they are invulnerable, like Boss Tweed.