In A Doll's House, Dr. Rank professes his love for Nora:
Dr. Rank abruptly admits that he loves her. Nora tells him that he has done a terrible thing in admitting this.
Nora is embarrassed. The evening is drawing near and it is getting dark inside the house. When Dr. Rank admits his love for Nora, Nora gets the lamp and lights it. The light is real. It is not artificial. She is uncomfortable when Dr. Rank shares his love for her. She tries to light up the house. Nora is uncomfortable in the dusk lighting. The intimacy of the dim lighting causes Nora to feel uneasy. She is definitely caught off guard when Dr. Rank admits his love for her. She even tells Dr. Rank that he should not have admitted his love for her:
NORA:[at the hall door]. Helen, bring in the lamp. [Goes over to the stove.]
Dear Doctor Rank, that was really horrid of you.RANK:To have loved you as much as anyone else does? Was that horrid?NORA:No, but to go and tell me so. There was really no need—
Ibsen is suggesting that the truth about Dr. Rank's love has been hidden. When Nora lights up the room, the truth has been revealed. Nora continues to chide Dr. Rank for his clumsiness in telling her of his love for her:
To think you could be so clumsy, Doctor Rank! We were getting on so nicely.
No doubt, Nora lights up the room to get rid of the awkwardness of Dr. Rank's confession. With the room lighted, Dr. Rank can clearly see Nora's frustrated expression on her face. Nora does not want to lead Dr. Rank on any longer. Nora and Dr. Rank had their own hidden feelings, one for the other. Now, that Dr. Rank has been so candid in his profession of love, Nora is extremely uncomfortable. She calls the maid to bring in the lamp. The lighting is not artificial. Nora desires to shine the lamp brightly so Dr. Rank cannot continue his intimate comments in the dark or the dusk lighting.