If you think about taking shots, he is taking shots at both Mitch and Nick, then also the wide receivers saying this year you better be ready and get your details right.
I liked it that he went at the wide receivers a bit to say it's not just all on the qb, you need to get your crap together too or we will have conversations on whether or not you are on the team.
As I said in another thread, I listened to Adam Jahn's on his podcast. He commented that Dalton was not just throwing checkdowns either and looked ok. Dalton himself, from a mentoring point of view, said he talks to Fields about where his eyes go. I can't remember if he specifically mentioned what keys he looks for in defenses. But, that is a large part of the value that Dalton will bring to Fields - hopefully showing how you can speed up your progressions and reads by reading the keys right and putting your eyes in the correct starting place based on that and the playcall. I always got the impression that was one of the issues with Mitch - they used to talk a lot about correct eye placement which makes me think that was a detail that he missed at times in the games.