I missed the match but posters here report that Nadal improved his pace of play and played more agressively.
I just had the impression that after a conservative start when he played very short, and his opponent was at a practise-match level, he thought about trying to hit harder for his practise again in the beginning of second set.
Nadal can hit very hard in practise matches, that's something we've known for long.
It doesn't mean necessarily that it's the tactics he will always use.
Besides, if he hits hard because he can't move well (and his move was not good in the start and has not been tested really, sometimes in the end of first set, he hit shots in such a way that he wouldn't have been able to move back), it's not good news either.
Wait and see.