This is a combination of the Continuity Camera Holder remixed by @thematchless for fitting the legacy Apple Thunderbolt Display and another mount for placing the iPhone lenses at eyeline height for a better framing and lightning. Including also fittings for iPhone 13 and 15 Pro without case.
The author remixed this model.
Combined those designs primarily to have the phone mount of the former and the monitor sizing of the latter. Left the second mount to expand the possibilities rather then redesign the back hooking