To be fair, typically in America (outside of major cities and certain planned neighborhoods), 4 minutes away implies by car. Even if driving only 20mph (unlikely), the pizza shop would be a minimum 1.3 miles away, which would be more like a 30+ minute walk for a pizza.
On top of that, there’s almost no safe walking paths by design. You would likely have to traverse major roads with no sidewalks, crosswalks, or even pedestrian stop lights.
It’s an unfortunate design that many are stuck with.
She’s not necessarily angry at the guy, just angry in general. She might prefer to be alone after something irritating or otherwise anger inducing happened, and he’s trying to add a little love to remind her that he’s there, then leave so he can give her space to be angry.