The onboard shot from this is particularly eye opening:
Seeing it i see something completely different than today. Webber went near the wall before Massa even try the move so that it will discourage him from taking the inside. After Massa tried the move nonetheless knowing fully well how little space he had, Webber didn't move closer to the wall or try to stop him, he continued straight. Schumi wasn't as close to the wall when Barrichello tried his move, so Rubens didn't expect a risky close up to the wall as much as Massa did. Then Schumi started pushing him to the wall, Webber didn't push Massa anymore after he got out of his tow to overtake. Schumi on the other hand pushed and pushed forcing Rubens to avoid him until he put him a lot closer to the wall than Webber ever put Massa.
By seeing the photo i thought Webber did something similar just with a little more space but this video shows very clearly that it wasn't like that at all.
Webber went near the wall before Massa even try his move. Something he had every right to do since he is free to choose his line as long as he isn't pushing anyone by his side. Massa knew there was a little space there and he did it knowing very well how much room he had before trying. Rubens was pushed a lot more dangerously and closer to the wall and that happened while he was already side by side with Schumi. When he tried his move he had no idea he was gonna end up so close to the wall.