A Sony A7iv has threads for attaching lenses. An iPhone does not. It's like if I feed you a six-course gourmet meal and tell you "I made it on a camping stove"

A Sony A7iv has threads for attaching lenses. An iPhone does not. It's like if I feed you a six-course gourmet meal and tell you "I made it on a camping stove", when in fact the camping stove was just used to keep one of the sauces warm while everything else was made in a professional kitchen. That's what is happening here; there are some shots that the iPhone is physically incapable of making, so they used something that is capable of it and filmed that on the iPhone. "Shot on iPhone" is implicitly promising that you can make what you're seeing if you have an iPhone. NOT that you could make it if you have an iPhone plus some additional equipment that is capable of making those shots, that nobody would even imagine using. For the most part, none of us even knew such a thing existed, although it's not hard to imagine theoretically. "Shot on Sony A7iv", on the other hand, is pretty obvious to anyone at all familiar with photography that it is only telling you what camera body was used. In fact, people with any level of familiarity would respond with "ok, what's your point?" because the model of camera body is a relatively small detail if you're trying to describe what you used to make an image. What lens, exposure, postprocessing, etc? It's like admiring someone's work in a gallery and asking "what did you use to make this landscape scene?" and getting back "paint."