I noticed a white hue on the top of the screen and ONLY on the homescreen. I thought it was a Fairphone 5 issue, but now i noticed it on my Nothing Phone 2a (photo)as well. What is it?

After i got my Fairphone back from the repaircenter (they thought there was something wrong with it), they told me it was an intended design. However, i see other people mention they don't have it.