Hello Emmanuel5652,
Thanks for posting in the Apple Support Communities.
It sounds like you may be noticing the TrueDepth infrared lights, so let's see if that's related. This can be expected to be noticed under some conditions, so check out the following resource for more details: About Face ID advanced technology - Apple Support
When viewed through certain types of cameras, you might notice light output from the TrueDepth camera. This is expected as some cameras might detect infrared light. Some might also notice a faint light output from the TrueDepth camera when viewed in a very dark room. This is expected in extremely dark settings.
Let us know if that seems to be what you're noticing. If not, provide more detail on where you're seeing this on the iPhone, along with any additional details to understand your configuration.
Have a great day!