@frusonne65 said:

The series did not offer any explanation as to why the miniaturist sent the doll house items. It only created unhappiness. Did the book offer any explanation?

I haven't read the book but here is a synopsis of the book. There is an explanation (I guess?) in the last paragraph.

https://en.wikipedia.org/wiki/The_Miniaturist#Synopsis

Hi Thank you - good idea to read synopsis of the novel if the show is based on one and the ending of the show is unclear. I had forgotten about that :-). I actually once read the synopsis after seeing "The crimson petal and the white", only to find out that the ending in the novel was even more ambiguous. Now I find that the actions of the miniaturist were pointless - it did not serve as a warning, mitigation or anything smart that Nella could use to prevent bad things from happening. How exciting it would have been if for example the miniaturist had been a distant relavative knowing about a secret that can't stand the light of day, but she found Nella was the one to deal with it. Now Nella is in a pretty bad pickle, no husband, a bad economy and an innocent child that needs a wet nurse whom she is probably also going to pay to keep mouth shut. I read there's a sequel coming out, but I bet the author does not address how Nella managed these obstacles as it is set 18 years after the events of the first novel.

You are welcome.