Soon after Emma Ganzarain moved into her boyfriend’s apartment in Oslo, the couple got to work on a redesign. They added light-colored herringbone floors, with radiant heating to combat the Norwegian chill, and taupe kitchen cabinets. In the living room, the pair swapped out a purple light fixture for a white one and replaced a maroon armchair with a chair of a similar size in off-white.

When the work was just about done, Ms. Ganzarain, 26, posted some before and after photos on TikTok. “All men need a woman in their life,” she wrote in the caption.

The reaction was not what she expected.

Her post has been viewed nearly 8 million times since it appeared earlier this month. It has also generated more than 55,000 comments, most of which are negative. Many people have accused Ms. Ganzarain, who had about 3,000 TikTok followers at the time of the post, of ruining her boyfriend’s space, replacing its warmth and character with a more sterile look.

“The before is better,” one commenter wrote. “After is very clinical and cold.” The person went on to note the renovated apartment’s “Patrick Bateman vibes,” a reference to the serial-killer protagonist of “American Psycho.”