Not sure I would call them incremental. Nor each snapshot (or even the first) being a clone of the system (which is contradictory to being incremental).

All snapshots ‘contain’ all data relevant to that snapshot. It is just that multiple snapshots can point to the same underlying block of data and when new block of data is written it is copied to a new location so old snapshots can still see the old blocks of data but newer ones see the newer blocks. If you delete a snapshot that is the only thing pointing to some blocks then those blocks are now considered free and can be overwritten. But other blocks that still have other snapshots pointing to them will remain.

So you can delete any snapshot you want and no other snapshots needs to change or incorporate any other changes - they all already point to all the data they need.