The ant
At the beginning of the movie, as she is taking the other alien’s clothes off, the protagonist finds an ant and observes it. The ant is important as it symbolizes her alien species and gives an explanation to their actions. The ant has the same body color as her, and the same role. She, just like the ant, is just a worker without a personal goal. Her only goal is to collect human meat for her species.
Skin
At the end of the movie, where her human skin is ripped off, and her true colors are shown, the alien woman immediately dies. It symbolizes vulnerability and danger of showing one’s true self to the world.
Red lipstick
Throughout the movie the alien woman constantly wears a red lipstick, mimicking the human women. It is a clear symbol of seduction and superficiality and one her “weapons” to rule men in.
A single tear
The alien woman at the beginning of the movie sheds a single tear as the protagonist alien takes her clothes off. It symbolizes her straying from her task and wanting to be a part of humanity. It serves to foreshadow the protagonist alien’s fate as well.