Using landscape mode in settings app

I have an iPhone 11 Pro while my wife has an iPhone XR. I saw her using her phone today and notice when she was in her “Settings” app she had the phone sideways and it displayed in a landscape view. Also when she puts her iMessages in landscape view her contacts show on the left while her message is in the right panel. I’ve scoured the internet for this option but haven’t found one. Her screen is literally the same size as mine so I don’t think it’s screen size. I know you can do this with the Max version and didn’t think it was supported on the non max version. What’s going on, am I overlooking something?