It is not clear to me from the Shapely documentation what is the precise definition of distance between two Multipolygons. I believe I read somewhere that the distance between two Polygons A and B is defined as the minimum distance from the boundary of A to the boundary of B.
If that is correct, does that imply that Shapely's distance between Multipolygons C and D is the minimum of the distances for all possible pairings of Polygons A and B where A is an element C and B is an element of D?