Juli Clover, MacRumors:

Apple today updated its Apple Store app with a new “For You” tab that offers access to order status, devices, accessory recommendations, services, reservations, and product tips, all in one simple to access place.

And:

There’s also a feature that’s designed to allow you to compare a new iPhone you’re considering purchasing with your existing ‌iPhone‌ so you can see the difference at a glance.

First, note that this is the Apple Store app, not the App Store app.

Second, I’ve not yet gotten this extra tab on my phone, which is running iOS 13, but I did get the new tab on my iPad, which is running the beta of iOS 14.