No that's not the claim. A control is to understand how your model works, it's not what you release as the final product.

It would be nice to see a logistic regression using at least some of the features known to be useful (including geography and income).

That way we can see how much of the performance is from magic AI pixie dust, and how much is from basic 19th century statistics.

Every time I read a paper like this, I have this Margaret Mitchell talk [1] in the back of my mind.

[1] https://youtu.be/XR8YSRcuVLE

Yep, these papers don't usually pass the sniff test. My bet is you can predict the phone brand from the camera grain and that correlates with geography & income.