Meta Study?
The only thing that makes sense to me is if this is actually a study/research into how to carry out "blind" research experiments.
1) Selecting for iPhone ownership seems arbitrary but it turned out to be the largest group. This was almost certainly done out of a prior assumption that this would be the case as a small group makes for bad Significance.
2) The only things that were done aith any scientific merit were all designed to ensure the test subjects did not guess the true nature of the test and skew results accordingly.
Sure, adding the brand recognition of "iPhone" in the title, much like adding "Star Wars" or any other popular cultural icon is a good way to get interest in your research (and to get it published far and wide) but I think that's secondary.
On reading this, the first challenge to the findings of this research would be "How have you shown that this phenomenon is uniquie to iPhone or even smartphone use and not due to cultural programming that a ringing telephone must be answered?"