Giaccherini, who moved to the Stadium of Light in the summer, has started in both of the Black Cats' last two fixtures in the Premier League.
"We are playing differently under Mr Poyet," Giaccherini told the Shields Gazette. "We've changed the mentality among the players since he arrived.
"And now we are proving that we can play differently too, and it's an advantage for us. I enjoy playing that way, and I'm happy to play in this team."
The North-East outfit are currently second from bottom in the table with just seven points from 11 games.