It didn't hit me until long after I played that the first shard of the new doll appeared before we even knew Ms. Sato was back in town. Does that mean the dollmaker knew who she was when Mrs. Sato mentioned her granddaughter, and he planned to "collect" her from the start? Was he just pretending he forgot her to lure her in, or are the doll shards just a sign that his compulsion is surfacing again?
The first shard appears mixed with Ms Sato's broken doll... a few seconds before we meet her granddaughter.
It can have many meanings but we cannot give you one clear explanation.
What's happening in the twisted mind of our protagonist remains a complete mystery...