Those 4 dots in the centre of velocity max line

This may be just a little off subject, but i would like to know what those 4 dots mean in the centre of velocity max line in the photo at the top of this page.
All the best

I am pretty sure it is just a visual to indicate that it is a re-sizable bar.

Seems weird to me as it really says i am in the centre of the page and that is all.
It was not there in Cubase 11.
I thought it was a drawing bug in the line.

The four-dot-design is new for Cubase 12. The functionality has always been there.
You can grab anywhere on that bar to resize the controller lane zone.