Going to have to call bullshit on this. If it was detectable at that range then he has a faulty phone. The iPhone is classified as an emitter and so it needs to undergo rather strict FCC testing to ensure that it does not emit outside of certain frequencies and at specific power levels. The device would NEVER have been approved if it emitted at this level into bands licensed to other uses.

6 meters is near field in that frequency range. The emission power is possibly well below FCC limits.

He said 20 feet away https://twitter.com/doctorcube/status/1301146339561164800

I doubt it. That probably wouldn’t pass the EMC testing. Exaggerating I suspect to back up the claim.

Really why is this a surprise when you can hear the phone blips and buzzes from the RF induced pickup on shitty hifi equipment.