The idea, here for the latest iPhone 11 series, is that you have a wired flash 'cube' with internal 700mAh battery (ignore the '7000' figure in the video) and you plug it in and hold it while taking flash photos with the iPhone to experience several times the native phone LED light power:
It's a nice idea, but there are cons. Not least that plugging this in doesn't disable the built-in phone LED flash, so you get multiple light sources. I'd have thought the obvious use case here would be to light your subject from an angle other than 'straight on', by holding the accessory off to one side by a metre or so. This isn't currently possible - maybe it needs a software update from Apple (under pressure from Anker)?
Given that many AAWP readers will be in the process of considering an iPhone 11 series device as a Windows replacement and given the 'All About' site focus on imaging through the years, I thought this accessory of interest, anyway!