Why do the stabiliser trim wheels not move exactly in sync? I've watched a few videos about the Boeing 737, and in particular because it's a bit of a current topic, about the stabiliser wheels in the cockpit.

On some of these videos, which are often in commercial flight simulators, we see the stabiliser wheels rotating backwards and forwards automatically. On the wheels there are white marks. However these white marks are often not synchronised and level with each other, for example this video, or this GIF below from here:



There are other videos where these marks are sometimes nearly 160 degrees out from each other. From my naive expectations, shouldn't these marks be within a a few degrees of each other to accurately represent that the stabilisers are at the same level?

Or, are stabilisers individually independent such that the left stabiliser may need a more acute angle of attack whereas the other may not?
The rear wing (horizontal stabilizer) of a 737 is effectively one piece. There is no separate left and right trim control. Both sides during assembly are attached as one.

This is just a visual illusion because the white marks are not aligned. If you manually move one wheel, both wheels will move.

It's worth noting that the white marks do not represent the position. For the full stabilizer travel, the wheels would make many, many revolutions.

The stab trim position indicators would show the position, not the wheels:


(source)