Maybe its a bit on the nose - they literally describe space as they describe space, ha ha.
What sculptural ideas are there?
Hole/inside
Top?
Stackable (verticality)
Re-arrangeable (unreliable monumentality)
The body in space
Artist-viewer negotiation/co-creation
Formal considerations:
Scale
Weight
Other considerations:
non-uniformity
non-precision
limited pool of gestures