to make the hole punch smaller. Usually you have a bit of padding around the sensor which is included in the hole punch. That's why the S10/S10 lite / a71 hole punch looks much larger than the a51/S20 Fe/a52/a72 one. Samsung also has a small holepunch with the padding like on the s20 and s21 however that uses the dynamic amoled 2x display which would be too expensive for the other phones to use. Instead, the a51/a52, FE selfie camera don't have that padding. That's why you get the black ring around it whenever it's in use (won't notice in the camera app as the background is already black but look at Google duo for example, or if you leave smart stay (if it's still called that) on it will blink with the black circle at the camera periodically). They do that to make the hole punch much smaller than it would otherwise be. As a by product of that you get the silver ring. However, I've been using the a51 5g for 9 or so months and it had the ring yet I don't really care much for it, I much prefer this method than the larger but no silver ring punchole like on the a71/S10 lite after comparing the two
