What is the small blinking light on my phone screen?
If you have a Galaxy smartphone with an Infinity display, you may notice a small flashing light which is about one pixel in size. This light is caused by the proximity sensor being activated.
Because of the minimised bezel and maximised screen size on devices with Infinity displays, such as the S20, S10 and Note10 series, the proximity sensor is located behind the display panel. On older models, the proximity sensor was located under the bezel at the top of the device.
When the proximity sensor is activated, a light may flash at the top of the screen on your device. This is normal and to be expected.
The proximity sensor has a number of functions including turning off the screen during a call to avoid accidental touches or when your phone detects that your face or ear is close to the screen when making or receiving a call.