Thanks for the hint. It’s a 7 so that’s why it’s rectangle. I’ve had iPhones since the 3GS but it’s hard to remember every change in the UI over the years.

Yea, there’s a lack of info. I was also thinking jailbreak in the back of my mind. If the phone was reset and set up as new the dock would be filled with some standard apps.

Have you tried a hard reset? Hold the lower volume and the standby button until the Apple logo appears. See what happens.

What does up to date mean? iOS 15? It already had rounded corners on the dock (I know, you can’t put apps there..). But this isn’t 15, is it? I think 14 had the rectangle dock. What does it say in settings/general/info?

iPhone 7 if “up to date” as OP states supports up to iOS 15.

How would he update iOS on an iPhone model that’s not eligible for that specific version? It doesn’t work like this.