This is the 12109th most frequent Polish word.
lusterka
"Side mirrors" or "rearview mirrors."
In this sentence, 'lusterka' means 'mirrors' and refers to car mirrors used for seeing the surroundings while driving.
Lusterka w samochodzie są bardzo ważnym elementem wyposażenia.
The mirrors in the car are a very important part of the equipment.
Here, 'lusterka' means 'mirrors' and refers to smaller mirrors often used for personal grooming.
Ewa kupiła nowe lusterka do swojej toaletki.
Ewa bought new mirrors for her dressing table.
In this context, 'lusterka' (mirror) is aiding observation, specifically seeing behind oneself.