In the picture, we can see Allen is holding the board with "No WAR", Pheobe is with the health care and I am with provide some jobs.
It means you can publish your speech or opinion freely. It represents the democracy. It shows that different kinds of people can speak out their ideas in different topics.
It is important because the society needs different ideas. Freedom of speech can let the government know what are people thinking about, then they can make some changes according to these speeches. It is good for our society.