* A bottle with a drop coming out: This is a general symbol that could represent various liquids, including nail polish remover, but it's not specific.
* A painted nail being wiped: This is a more specific, but less common, image.
* The letters "NPR": This abbreviation is used in written form.
Ultimately, the best way to indicate nail polish remover is to write the words "nail polish remover" or use a clear image or label on the product.