I’d be curious if there’s a standardized size(did not see an entry for “ice” in ISO 16520; am admittedly not enough of a standards wonk to delve too greedily and too deep) or a de-facto standard imposed by what the local block ice supplier happens to offer(those edges look more transported than molded on site; though that’s just a guess) they are working against.
Ice can certainly be formed; but it’s not just a joy to do and the proper options are likely to either be specialty or look like they came from the hardware store because they did; so it wouldn’t be a huge surprise if the block comes in whatever size is closest to right that also suited the needs of Kobe residents back when somebody built that big, old-school, ammonia chiller ice plant in the days before widespread refrigeration when block ice still attracted capital investment.
(edit: ran across a charmingly specific interest group, unfortunately for the wrong country, that reminded me that there might also be some transport industry related size conventions playing in to ice sizes.)
