Why does it hurt when you put sharpie on your skin & then take a picture with flash on the iPhone?

Okay, so there's this thing at my school where you do this:
1. Draw a black sharpie square on your hand
2. Take off your phone case
3. Put your phone camera directly on the skin where your sharpie mark is
4. Turn on the flash on your phone and then take a picture.
It hurts and stings a little bit. It's like a small shock. Why is that?

It has to do with a reaction of the chemicals in the marker and the light.

Is it harmful for your body?

Is it harmful for your body?

Is it harmful for your body?

The dark patch of sharpie absorbes more energy from the flash, causing the spot to heat up and make the skin feel a quick heat sensation, or a "Shock".

Nah fam that's just dumb

Nah fam that's just dumb

Nah fam that's just dumb

It prolly causes skin cancer

It prolly causes skin cancer

It hurts more if you use pen. Try it.