The behaviour is very different to hardlinks. The clone is a new file that uses the same blocks. When you modify the clone, writes are written to new blocks rather than the old ones.

So if I have a disk image that takes 1,000 blocks, and clone it - I now have two images that total 1,000 blocks. And if I modify one block in one image, I now have two different images that total 1,001 blocks. With a hardlink the modification would affect both images.

The way I visualise the difference, is that a directory entry points to a file entry, and a file entry points to a list of blocks. A hardlink is a new directory entry that points to an existing file entry. a linked clone is a new file entry that points to the same list of blocks.