When you use a facial wax strip for removing unwanted hair, what happens is that a portion of the skin (the upper part) can come out along with the hairs. When compared against the surrounding areas, this area would seem like a tattoo. The best thing would be to wait for the skin to grow back but depending on the reaction of the body to the wax, the hyperpigmentation
can sometimes persist. If the skin does not start to get normalized even after a period 2-3 weeks you should see a dermatologist
for further treatment.