Are you saying Ted Williams swung like the kid in the drawing? Ted would not agree with that swing. He was an advocate of upward path, as fastball had slight decline from higher mound/release point.
Did you tell the kid to swing the kid in the drawing? Keeping the shoulders level to the ground is creating a downward path to the ball.
What's California got to do with anything? Are you saying if you don't live in California, you don't know hitting?
BTW, did you meet Ted Williams? I did. I live 6 miles from Route 24 which leads to Lakeville, MA. That's far from California. But, it's where Ted ran his camps. In fact, there is still a camp run by a former student who was also the 5th pick in the first round. He also was a hitting instructor for four years with a MLB team (oddly enough in California). They've since moved the location, but it was a continuation of Ted's camp. http://playballcamp.com/staff.php
But none of that has anything to do with swing plane, and that the swing plane in the picture is wrong.
PS. you mention the TW video is a must see, then follow that with most athletes learn from "hands on" rather than video. Just throwing that out there. lol Some people are better administrators than instructors.