Let's work backward here.
Last of all, this is a beautiful feed from Kristaps Porzingis, who sees that a mismatched Derrick Rose is fronting Carmelo Anthony in the post and that he has a slim but useful angle to get Melo an easy shot. If Rose didn't front, Melo would still have great position and a big height advantage, with the threat to kick out if help came.
Second of all, this is a wonderful identification of the mismatch by all the Knicks who start on the near side of the court. Porzingis, Arron Afflalo, and Langston Galloway all agree that Afflalo should clear out so the Knicks can exploit the Rose-Melo mismatch, either by posting him up or beating a front with a good entry pass.
None of the above happens, though, without the thing the Knicks did first of all. On the preceding play, Doug McDermott (I typed "Jimmy McDermott" here at first then stared at it for 15 seconds trying to figure out what was wrong) missed a long jumper, then got back on defense. Derrick Rose is back, too. Carmelo Anthony booked it after the miss, and at the time of Derrick Williams' rebound, is down by the basket with Rose and McDermott.
Now! If the Knicks walk the ball up, none of this matters. The Bulls would get back and settle in, and someone would swap onto Melo so Jimmy "Doug" McDermott and/or Rose aren't stuck with him. That's not what happens! Williams snatches the rebound and GOES. The rest of the Knicks GO. This means the Bulls can't reshuffle. They must deal with the immediate threat, which is preventing a fast break bucket. And they do! But they do so at the cost of correcting the mismatch (Jimmy Butler, whose name is actually Jimmy, doesn't help matters by gambling briefly at halfcourt.)
Butler, Gibson, and Portis are all better qualified to handle Melo in the post, but they can't go take that assignment off Rose's hands because they have to deal with Williams.
Melo got an easy bucket off a great catch because Kristaps made a great pass because the Knicks identified a mismatch and created an angle to exploit because they prevented the Bulls from undoing that mismatch by getting the ball up the floor quickly. Pushing the pace isn't just for fast breaks. It's also for scrambling the halfcourt defense, denying them a chance to catch their breath and set up with purpose.
Like, this play was great, and/but it still would have created a good look if Afflalo pulled back and waited for a trailer. He's got the entire defense occupied while his teammates get up court.
The Knicks did a great job of hustling the ball up the floor Saturday night, and I hope they keep that up. Even if pushing doesn't produce an immediate bucket, it can generate looks later in the play.