The appear to be the most perfect cabbages I’ve ever seen. I can’t imagine they aren’t very expensive given the labor involved.
This is, after all, the country that invented square watermelons which sell for up to US$ 200.
Wikipedia notes, in the article linked above,
Although cube melons were originally created with practicality in mind, the cost is prohibitive. The cube shape of the watermelon can only be achieved at the expense of its contents. To retain the proper shape, cube melons must be harvested before they are ripe, rendering them inedible.
There were guys in the Columbia River Gorge area growing winter leafy produce under ground-level 4mil film cloches that elevated by the plants. The frostbite prevention involved the irrigation. I never tried mastering the art myself but it always struck me as particularly interesting for northern climates even though the caloric content would have been virtually nil due to low insolation. Nevertheless, it is nice having fresh salad year round.