The first shot is a LONG SHOT / orientation shot where the camera is placed far away to give a view of where the character is and the situation. This shot introduces the beginning of the scene, which is Clark Kent seeing Lana Lang after escaping from the piping system with Lex Luthor. The audience sees the location and is aware of the situation behind the characters, because of the long shot. The shot also makes the character appear lonely due to the amount of space surrounding the character. Clark Kent is placed in the middle of the scene and is standing still, while the characters behind him are in motion.
The next shot is the MEDIUM SHOT / information shot. This shot confirms that it was a specific character in the long shot. This shot is a continuation or further development of the actions that were in the long shot and are in the scene. Here, the shot confirms that this is indeed Clark Kent in the scene and the audience gets to see the reaction on his face as he sees Lana Lang.
The last shot is the CLOSE UP shot / important detail shot and it zooms in on the character's facial expression where the audience can see the emotions and feelings the character is expressing. The shot should naturally flow after a medium shot, but is emotionally revealing. Here, the audience sees how emotional Clark Kent is as he sees Lana Lang, noting that this expression is love.
Here's a bit more of the scene: