Ed Miliband arrives in Wirral West

Ed Miliband arrives at a venue to give a talk on immigration. He is greeted at a school and prepares to address a relatively friendly crowd. The event is not just about impressing those present but also about convincing the wider public of Labour's stance on immigration, especially in light of challenges from UKIP.

What does Ed Miliband need to do to impress the audience in the hall?

What is the significance of the people outside the hall for Ed Miliband?