Looks a little like both theories are correct.
She was tactically much better today. Got to the rail well for the second and third turns, so saved some distance run compared to the Trials final. More importantly, she made one big well timed move and took it all the way to the front. Trials final was a partial move, third runner to the outside, and only took it halfway up the field. Left her in the final turn well outside with another move to make in last 100 and she couldn't do it.
BUT, at the same time, it was clear she simply felt better and had stuff today that she didn't have last week. Much smoother today. Acceleration into her move was more fluid. Watch her form carefully in both races. Very different. She tied up last 100 last week. Today she just smoothly flowed farther away from the field.
Impressive run indeed.