SIT-A-LONG with Taigu: The sound of a bell

In the very begining of Shobogenzo, Dogen quotes a famous poem of Nyojo, his teacher:

My late master, the eternal buddha, says:

Whole body like a mouth, hanging in space;
Not asking if the wind is east, west, south, or north,
For all others equally, it speaks prajñā.
Chin ten ton ryan chin ten ton.

Free, careless, empty, the bell and the sound cannot be broken in two. Is the bell just a bell? Isn't the bell bigger, much larger? How large, how big is it? And where are you in the picture?