Disclaimer: I do not own Harry Potter. In case it isn't obvious.
2. So Like Your Father (Part 1)
As long as Al can remember, people have commented on his resemblance to his father. It's true that they have the same green eyes and messy dark hair, but that's about the extent of their resemblance. Al is tall for his age, and pale. He's thin, as was his father, but on Harry Potter the impression it lent was one of youth and innocence, especially when combined with the owlish glasses. Al simply looks wild, in a fae sort of way, especially since his green eyes gaze out sharply at the world, unhindered by lenses of any sort.
Personality-wise, they are different again. Harry is quiet, but commanding when need be. He is respectful, polite, and considerate, though he has to try hard to control his temper sometimes. Al is quiet(as long as he is separated from James, who knows, in that intimate brotherly way, how to push all of his buttons) in a watchful way. He stays in the background, so people don't realize just how much he really knows. He understands, for example, that Rose has a deep need to be in charge, so he goes with the flow and lets her think she is. He understands that everyone feels he is destined to be just like his father, or even his namesake Professor Dumbledore, so he gives the impression that he is following in their footsteps. It bothers him, though, when James teases him about being a Slytherin, because Al knows that he can be cunning and has ambitions. He worries about what would happen if he was Sorted into Slytherin, what would happen in his family, but his father's words are a reassurance, as well as a revelation. Perhaps Al is more like his father than he thought.