Pink ring with grey background appears on iPhone 13 mini screen

So I have a question… my iPhone 13 mini will randomly if I play with my case there is a combo I am not sure but I will sometimes hear a doink noise and then a large light baby pink ring appears in the middle of the screen with a grey background and just as quick as it appears it disappears. Any clue what it is?

[Re-Titled by Moderator]