You can't tell anything from the replay. That's why it's so different to attend these games if you can. Plus we don't know how he looked in the drills and small area games the previous couple of days which is what the coaches and development staff actually use to help gage where a player is in their development and what they can offer the team.
I disagree that you can’t tell anything from the replay, but I do agree that overall the tournament shouldn’t really be used as a barometer for how well a player is doing (which is why some of us should probably cool it with the heaps of praise, too). Even the coaches said that this is moreso about getting familiar with the organization and using it as a team building exercise, more than the on-ice stuff.
However, if Rosen had a bad dev camp it’s not necessarily a bad thing. Sometimes guys need a wake up call. Tage Thompson said in his post season press conference that Granato sat him down prior to the start of the year and said “it’s now or never for you” and how that stuck with him (as a side note, I wonder if a similar conversation is had with Mittelstadt this year).
Our organization has preached honesty with players, and if KA/Peca or any of the dev coaches had issue with how Rosen did, they could very well say something like “that won’t cut it in the AHL, much less the NHL”. That could be a wake up call for what sort of training he needs to do or the intensity he needs to play with if he’s going to make it. If you’re going to make mistakes, a dev camp would be a great time to do it.