What dramatic effects are obtained by its placement here?

The dramatic effect comes from the fact that Nora and everyone around her know that her "help" will ruin her marriage. It's not her job to help or to fix things......... Torvald wouldn't want her help and even worse he wouldn't want her to break the law. What she's done removes her from the role of subservient wife and unsurps Torvald's place as the head of household.