Unlikely. The USB protocol requires one master and one or more slaves (or whatever less charged nomenclature you prefer). In all likelihood UEFI will blindly assume to be the master while Android and iOS require negotiation to figure out who's boss and what interface to present.
Although given UEFI it might be possible to patch that functionality in.

It does, though with an app that exposes the iso.

Edit: Right, i thought it was EtchDroid. I think it was DriveDroid (with a broken cert)? There's also SimpleBoot now.

There's a tool, whose name I forget, which is included in Kali NetHunter to do just that. It does whatever trickery is needed to present the phone/tablet as a bootable thumb drive. It requires root and, to my dismay when I needed it, I never owned a device that was rootable to fully use NetHunter. It could do a lot of other cool stuff via USB too; phone as a Bad USB, Rubber Ducky, automated Windows login bypasses, etc.