This political cartoon, "Under the Thumb," was published by Thomas Nast, the scourge of Tweed and the Tammany Hall Machine. In the cartoon, we see the Tweed has the city under his thumb, meaning he is in complete control. This cartoon depicts New York under the thumb of Tweed, who is the Boss there. Adding "Well, what are you going to do about it," supposedly a quote from Tweed himself, shows that he knows what he is doing, and knows that he can remove any threats he sees fit.
Yet another cartoon by Nast showing the actions of Tweed to New York city. This cartoon, "The Brains," depicts Tweed with a bag of money as his head. This shows that Tweed is in control, the brains, but he is only thinking about money. This monetary thinking is shown by the bag of money instead of his head. The fact that Tweed has his hands in his pockets shows that he is OK with this, he isn't phased by thinking only of his own financial gain.