Apple's "Pro" iPhones usually look and feel a lot like the regular ones, just with some added features stacked on top. They've historically had better screens and more flexible cameras, and there has always been a Max option for people who really wanted to blur the lines between a big phone and a small tablet (Apple's commitment to the cheaper "iPhone Plus" idea has been less steadfast). But the qualitative experience of holding and using one wasn't all that different compared to the basic aluminum iPhone.
This year's iPhone 17 Pro looks and feels like more of a departure from the basic iPhone, thanks to a new design that prioritizes function over form. It's as though Apple anticipated the main complaints about the iPhone Air —why would I want a phone with worse battery and fewer camera