Myers C.A.D.-cartoons are a total joke.
Myers deliberately-deceitful lie's were simply and totally exposed by Martin Hinrichs, long ago, as Myers C.A.D.-lies about the 6'0" JFK being Myers-bigger than the 6'2" Connally in the Myers/WC-swallower's to (fail to) try and force swallowing their impossible "magic-bullet theory"
Kennedy and Connally were essential the same size when seated; most of the height difference was in the leg length.
The camera angle in the 3D clip was such that the bottoms of Kennedy and Connally appear to be nearly at the same level, but Connally's seat was lower and more inboard than Kennedys. This would be better seen in a profile-view with minimal perspective. This view instead has a lot of perspective. Kennedy simply appears larger because he's closer in space to the camera than Connally.
Here's a photo with a similar (though not the exact same) camera-view as the Myers 3D clip. One can see that Connally "appears" smaller than Kennedy. The Myers 3D clip is much more closer to the figures in the car than any photographer was on the day of the assassination (with the possible exception of a few pictures taken by Dillard at Love Field). Therefore the difference in the size of the figures is more pronounced in the 3D clip.
Photos taken from the opposite side that have some perspective (the camera is near the limousine) make Connally "appear" larger than Kennedy.
A film frame taken from the right side and to the front of the rollbar shows the two men roughly equal in size. This is because the angle results in Kennedy and Connally being equidistant from the camera (ie: Connally's jumpseat -- being more inboard than where Kennedy was seated -- is now closer in space to the camera, which brings Connally into the same plane as Kennedy, thus making them the same size to the camera).