What does Flavius mean when he tells Marullus to “disrobe the images if you do find them deck’d with ceremonies" in the first scene of Julius...

This quote is from the first scene of Act One. In it, Flavius and Marullus are expressing their disdain for the commoners who fill the streets of Rome to celebrate Caesar's victory over Pompey. These two men not only sympathize with Pompey, but fear the influence of the mob that so vocally supports Caesar. Even though it is also the feast of Lupercal, a festival in which the city's statues and monuments were regularly bedecked with decorations and flowers, Flavius says that Marullus should remove the "festivities" because Caesar's victory over Pompey is nothing to celebrate. When Marullus voices some reservations about removing the decorations from the statues on Lupercal, Flavius tells him not to let any statues "be hung with Caesar's trophies" and to drive the Roman commoners from the streets, breaking up the public celebrations of Caesar's success.