The theme of this and the entire Harry Potter series is that love can conquer anything and that even in the face of absolute hopelessness, hope can still come. Neville in this scene talks about that. He says that even though Harry is gone all is not lost. The theme is actively communicated in the dialogue of Neville.
The video uses shape to show the shift of power. At the beginning of the scene, Neville is in a wide shot and Voldemort is in a close up shot. As the scene progresses and Neville stands up for himself he becomes bigger in the frame. Neville in this scene represents hope, and this action of making him bigger portrays the theme of a growing hope. There is also a contrast between the two sides. The Hogwarts people are all wearing civilian clothes. On the other side there is an affinity between the death eaters in that all of their clothes are the same.
Space is demonstrated through tension and release. The tension builds all throughout the scene. It builds when the death eaters laugh at Voldemort’s words. This also gives the area a sense of depth and space given that it is echo-like. The tension is released once Harry comes alive and and rushes back to the castle. Again, here we see space utilized well. The spells have to travel very far and the explosions are farther away, giving a sense of large space.