You're too focused on the iphone example.

Let's go with this:

I'm going to assume you agree that people, in general, assume certain things based on how other's look. We see dundee hat, and assume an australian. We see a star trek shirt, and assume they like star trek. Etc.

The singular direction of assumption I think, is obviously true.

But this mode of communication has two parties -- you, and the person/people looking at you.

Once we realize that other people are assuming things about us, based on what we have, wear and show, then the next step is to realize we can shape their assumptions, by doing two things:

1. Understand what things lead to what assumptions

2. Decide our target assumption, and change what we show to lead to those assumptions

So, like a bird with a mating call, we can signal to our peers what interests and goals we have, which they can choose to follow to reach us.

And like a bird with a mating call, which has certain qualities and factors governing fitness of the bird, we can be better or worse and producing stronger signals, and a poorly constructed signal can instead work against us -- If I want to be known as a nerd, I better not confuse star trek and star wars (even in honest forgetting) lest I expose a new signal, of a fake nerd.

And vice versa, we follow the mating calls to those that interest you. The iphone tells you nothing -- its not a signal you'll follow. For someone else, it might be a valuable signal. But for you, its not, and that's perfectly fine. You listen to other calls. Like perhaps, those that signal a preference towards "practical" thinking and needs.

> Having a fancy phone/expensive says precisely zero to me about someone's capacity to be interesting.

I disagree. Fancy/expensive phone signals conformity. Shitty old non-smart phone? Now that might be someone interesting!