Probably influenced by the most popular JavaScript library for achieving this type of layout, Masonry[0]. The author notes at the end of the article:
> But do expect the name of this value to change in the future. And perhaps prepare for a future where we call this “columnar grid” or “Grid Level 3” instead of “Masonry”.
> But do expect the name of this value to change in the future. And perhaps prepare for a future where we call this “columnar grid” or “Grid Level 3” instead of “Masonry”.
[0] https://masonry.desandro.com/