That's not how I read it...to me, it looked like this:
"He needs to get in his mind that he can help us and that he’s going to push it hard on every single play like the guys ahead of him are doing."
He needs to get his head right. He's not putting in the required effort every play (as Lilnaith said, this was a knock of Bryant's at Clemson as well).
"If you watch Antonio Brown, he scores on that second play [against the Bills last Saturday] because that’s how he practices."
Antonio Brown gives 100% effort every minute of every day, and he's a great receiver because of it...
"Every day in practice when he catches a slant he’s going to score even if guys touch him down. That’s how he practices and that’s how he plays and that’s what transitions into big things like that."
...Bryant isn't finishing plays to the very end/running through. He's going through the motions. A QB wouldn't mention this very specific aspect of practice if there wasn't something to it.
"As a young guy [Bryant] needs to keep learning from the veteran guys, and I think he will do that because he wants to be a great receiver.”
He's a talented guy who's a bit immature and needs to pay more attention to what the guys ahead of him are doing, especially from an effort standpoint.
Again, this shouldn't be a big surprise. One of the biggest knocks on Martavis and why so many of us were hoping he'd stay (even beyond our own selfish motives) was that he's always gotten by on his incredible natural talent but hadn't developed his game enough upstairs (where it often counts most in the NFL). This obviously isn't something he can't come back from...let's just hope he starts going hard every single minute of the day.