The Untouchables - Shot type Effects and Reasons

This clip was taken from The Untouchables, a 1987 gangster-crime film, set in the times of the Prohibition of alcohol in the USA.
The scene begins with a camera tilt, which ends up as a very long crane shot. This establishes and familiarises the audience with the setting. This is also the first time we are introduced to the characters in the scene. These are probably wealthy and important people (emphasised by costume and decor of the setting.)
The camera then moves to a long shot, making the audience feel as though they are being 'reeled in' to the scene. The camera remains still for several seconds to focus our attention on the main character, Al Capone (played by Robert De Niro). During this time, he makes his way into the centre of the frame, clarifying his significance as a character.
The camera then moves to a high angle so the audience see the characters ascending the stair case. This shot lets us see the surge of members of the press follow Al Capone up the stairs.
The camera then switches to a low angle. The effect of this is that it makes it seem as though Al Capone is towering above the audience. This strengthens his importance and prominence as a character, making him appear more dominating. He also takes up a large proportion of the frame.
Then we are taken to an Over-the-shoulder shot, looking over Al Capone. This gives the audience an idea of how many people are gathered around the main character, reinstating his vital role.
Then we are taken back to the low angle medium close up of Capone. This shot is also a frame with in a frame, as we see the character through the arms of the Press. This gives the effect of making the audience feel more directly involved in the scene. The camera stays in this position while the character is talking, to keep the focus on his dialogue.
As the character turns to walk away, the camera also turns, so the audience feel as though they are moving with the character. This also gives the audience the ability to see the desperation of the press to keep Al Capone talking.
Then when the character starts speaking again, the camera re-visits the previous position at the low angle, which brings the focus back to the character's speech.