He's going to the S&T.
A couple of things. Notice the umbrella out in front of Grant. I think this is a great drill for all golfers, particularly high handicappers who come over the top. I use this drill with my problems coming over the top. Simply aim at the umbrella, but try and get the ball starting out to the right of the umbrella. If you come over the top, the ball will start left of the umbrella. I'm sure Grant isn't worried about coming over the top, but probably working on fades, draws and other stuff. But still a great, simple drill nonetheless.
As far as him changing to the S&T (and I'm sure I'll get a lot of questions on it, so I'll answer them now), I do wonder why he's changed. And it's not a knock against the S&T, it's that even if he improves his ballstriking he's already one of the best ballstrikers on Tour. There's only so much he can improve it. Furthermore, Grant was quite long off the tee in his prime so going to the S&T, which really isn't known for power is well...questionable. However, I believe he's had some injury issues in the past few years and the S&T is actually good for the back if you're athletic enough to execute the pattern. Grant certainly fits into that category.