Yes, I have.For someone new, with no reviews and no other types of references available, that strategy seems like a wise one to implement on a regular basis for sure.
Nowadays, almost everyone has either a phone capable of providing this sort of authentication, or a computer with internet connectivity and a digital camera with which they could also easily comply with that request.
It's very reasonable for providers to require at least one verifiable reference for new potential clients, affording them the opportunity to be selective in who they see without taking the risk (or wasting the time) of having to do so in person. Notme's suggestion seems like a sensible, respectful and reasonable approach to finding an almost equivalent means of screening new and otherwise unverified providers.
I say "almost equivalent" because, while a current phone pic that matches up with a provider's ad pics provides reasonable assurance that the girl that answers the door or shows up on your porch will be the same as the one you saw pictured in her ad, it doesn't necessarily mean that her services will also end up being as she describes or that she doesn't have some nefarious intent in mind, etc. While on the other hand, a bonafide reference from a legitimate provider regarding a client carries with it an assurance, not only of the client's genuine identity as a client (ie, not LE), but also that the individual is of a reputable nature (ie, not a thief, not an abuser, etc). For these reasons it seems entirely reasonable to expect that new, unverified providers should be willing to either provide a current phone pic or, in some other fashion, authenticate their identity. In fact, given the seemingly rampant proliferation of bait and switch operations, it may very well eventually become the norm as we all become more and more familiar with and in possession of the wireless capability to do so.