Re: I lost track somewhere
"take a photo of it with your own phone while you're mugging them. You can then show the picture to their phone."
The article mentions picking which bit of the picture is used to authenticate: That suggests just having a picture, or the item, isn't enough.
It's still a stupid idea, of cause: What if someone has stolen your watch, or you've just lost it? Or you simply don't have it on you that day? Yes, other 2FA's can suffer from the same problem and potentially worse ones (battery's run out on the dongle, your phone's got locked, someone hacked your e-mail account and locked you out and so on), but you can get most of those things sorted without resorting to the failsafe option (one use password to bypass the 2FA, then a 2FA removal password to remove the option before creating a new one as an example).
That won't stop people from loving the idea, however - at least until they've lost the item they used.