Yeah, the lack of explanation sure doesn't help.
As far as I can sort it out, lightwhips are supposedly similar to regular whips, the "light" part comes from the many emitters on the whip's 'thong' (I imagine lots of tiny lightsabers if it is of any help).
Anyway, deactivated it shouldn't be any different than a normal whip (presumably made out of metal), while activated it should have the properties of a lightsaber (cutting through stuff, deflecting stuff, etc.) while only its strength could (emphasis on could) differ.
Still, parts on Wookieepedia confused me as well:
Lightwhips generally functioned on the same principles and mechanics as lightsabers, emitting a coherent beam of energy
(notice it saying 'a coherent beam of energy'), and
the plasma in the blade had no cell barriers to keep it straight
which (as far as my English skill goes) could indicate that the whip's thong does not have a 'physical body', but appears from the hilt upon activation, much like the blade of any other lightsaber (which would make even less sense).
I would so love to see one in action...
So yeah, I'd say the first method is more..."feasible" than the second, in which case seemingly only lightwhips use this method, using emitters, at least I've failed to find "lightsabers" with curved-blade, or lightaxes, lightscythes, and so on. But it's off-topic.