Notice at the end of the play how Nora explicitly identifies herself with a doll to explain how she has been treated by Helmer during their marriage:
I was your little songbird just as before--your doll whom henceforth you would take particular care to protect from the world because she was so weak and fragile.
This clearly indicates the way Nora feels that she has been viewed by her husband. The fact that she is a "doll" indicates that she is an object that is owned by her husband. She is not recognised as an independent human in her own right, and she is certainly not given agency to act as a human in the play. From the start of the play, Helmer patronises her, treating her as if she were a child, calling her a "skylark," a "squirrel" and a "squanderbird." Nora engages in childish games of concealment with him and acts in a very immature way. It is clear that, as Nora says in the final act, that when she married Helmer he took over where her father had left off, arranging everything so that his opinions became her opinions.
The "doll" is therefore a very important piece of imagery because it points towards the way that Nora in particular and women in general were objectified and not treated as adults, and were seen as a possession to protect and look after by the patriarchal society in which Ibsen lived.
Torvald does nit take Nora's concerns into considerations,He thinks that Nora is a childish woman who needs his care. Torvald is controling Nora's life, making deccissions for her , calling a squerels ,songbirds, etc. He tells Nora that she needs his care because she's featherbrain