My infrared camera is not showing up/flashing.

Hello! I’ve recently watched some videos on yt where people are trying face id and I noticed something quite peculiar, that I haven’t seen before on my iphone. Every time they use face id a red light shows up and flashes, the fact is that on my iphone I’ve never seen one before.

Notes: i have a screen protector on,but it doesn’t seem to block any sensor,because face id is properly working,and before I put the screen protector on(when the phone was ,,naked”) tbere was still no light.