"Of course we can go in the middle, here, here, close to one foot close to another, anything is possible, in that, tango today" more or less a quote
What come to mind here, as an illustration of how "geometry" can affect your dance, is that it's much easier to lead an "overturned ocho" if your center is "to the right of" your parnter's if you want to lead an ocho to your left. Etc.
It seems that she is mostly remembering how "natural" and "comfortable" it feels, though, to NOT be "off center" with your partner.
So, I agreee with btm's interpretation.