Seth...really doesn't appreciate the restraints. The moment they snap on a sense of panic fills him, instinctively trying to get out of them. And when that doesn't work he almost starts panicking even more, before remembering his decision to try and be better, and how panic didn't really do any good.
So he instead starts doing breathing exersizes to try and calm down somewhat.
He's still super unnerved and on the edge but there's not really anything he can do right now but go along...right?