the word empty is really being analysed far too much.
it's the same with suchness....
i had an open discussion with The Tulku that it did not make sense the way it is used....
there was an English teacher in the group who understood the concern...
M y take on the discussion was; all in all it is the best they came up in order to point to something for us English to work with...
"they "as in the first translators of Buddhist doctrine into English...
Western thinking wants language to be succinct. Even a metaphor is succinct....
now

Buddhist concepts

using emptiness and suchness...wowza....drop succinct and discuss...
no better still practice and study and practice and study...
i think without practice these concepts are never realized.... intellectuality it just doesn't cut it...
i may be wrong Some might be able to "get it" but i came to my understanding over a few years of study and practice....i finally saw it...
i recall the Gakki and Nichiren Shoshu priests trying to explain co arising and inter dependent ..i think they had the indo Japanese word Ku Ke chu ...meh i forget.......20 years anyway and until i had a Tantric teacher....it never hit home with the beauty of the philosophy of it all...
sunyata....
here let this play in the background....1;33 and it sings of sunyata....
http://www.youtube.com/watch?v=YsBjA6CO1jU