[Tango-L] Leading and following

[astrid]

It is much like the concept of being on axis.  Some
teachers will tell beginners that they must come to their
axis before they take the next step.  They end up doing
this "stop-n-go" tango.  Eventually, they learn that they
really need to just pass through their axis, which can only
take a split-second.  Split-seconds is all it takes to have
a dialogue in tango.

This sounds bizarre. Like, while they step, they would be off their axis.
How can you "pass through your axis"??