Cylinder Editorial confusion

Could somebody please help me with the vertically aligned circles case when W/2 < H/(PI+1).

As in the previous case we could then
move circles a bit and this will allow
us to increase D.

How are we able to move the circles in this case could somebody show it pictorially.I understood the movement in the horizontal circle case.In this case if D=W/2 and X=W/2 then we won’t be able to move the 2 circles at all.