[LAU] Ardour: the orange mobile squares in monitor track

[jonetsu]

Thanks to everyone who shared tips on how to use Ardour.  I see that up
to now I haven't used much of it really and the recent tips on hardware
monitoring are great and I'm still experimenting.

At the beginning of a new session I've added a hardware monitor track
with 4 outputs PCMs 1 to 4.  I'm still not doing much with it at the
moment and noticed that in the mixer window there's a fader for it
along with a space at the bottom containing 4 green dots numbered 0 to
3.  When dragging them in the square space the mix would slightly move
sideways.  That seems useful.  But what about the orange squares
located at each corner of the space ?  They also can be moved but seem
to change nothing - what is their purpose ?

Cheers.