Two things that I like by watching those. First, he's moving well in the pocket which Tannehill never did well.
But what I really liked was that Rosen was making plays with his legs on the fly. Tannehill could run but mostly when that was the called play. He was never really good at improvising on the fly. When things broke down it was a sack. I see Rosen takes off when thing break down and yes, I'm aware he was sacked 45 times but that O-line was horrible. Time will tell but there seems to be something there.
I think the key for Rosen will be to be assertive yet play within himself and the system. You want to be aggressive, but not out of control. Take what the defense gives you and play to win on every play. When the defense gambles make them pay! Oh, and hold yourself and your teammates accountable. It’s not ok to suck.