On the first shots Mcgonagall is walking through the corridors. A master shots which is a long shot of all the character is taken which gave the impression of a hectic situation where everybody seems to be in a hurry. As Mcgonagall is walking to pass the camera, the camera movement from still turns into a tracking shots. Because of that from what before seems to be a long shot turns into a medium shot that give more emotion and details as both of the character is having a conversation. As they reach outside as the character stops walking, the tracking shot stops and transfers into a dolly out even when though the characters are still having a conversation, the reason of this choice is because it turns out the conversation of the two is not very important and relevant to the scene following to the Hitchcock rule. Next there is a slight dolly in after the conversation with the students end. Now Mcgonagal talks to the other teacher. This conversation is far more important because it talks about the main issues of the scene, which is Voldermort attack.
The second shot is rather unique because it takes from the back of the characters. The shot comes from above then take a dolly in while going down (crane shot). The meaning of the shots is it shows that the characters wants to protect something, because of that it portraits the back of the character as a symbol of protection. The high angle represents that they are weak, just as the conversation the know that they can only stall, but soon the lowering camera angle makes them looks rather strong represents the strong will.
The third shot is the continuation of shot 1 dolly in, from a long shot in shot 1 it turns into a medium long shot. The fourth shot like shot 3 is the