Confusion about Partial Book Depth Streams

I’m currently very confused about the Partial Book Depth Streams and what data they send in order to construct a local order book. In the Documentation it says that the values are the price level to be updated and the quantity. However, comparing the data to the order book on Binance, e.g. here for BTCUSDT, this data does not match.

So, it seem that this data is just the change in the volume at the price level?

How to construct a local version of the order book like it is shown in the REST API, i.e. with the full volume for each price level?