@Cherie65- You are quite correct to be suspicious. Someone who would knowingly create a profile like that, intentionally hiding their face, probably had bad intentions. A normal person, using AirBNB for traveling and business to other cities, would simply have a standard profile picture of their face. There is no reason to do what that person did, other than the fact that they did not want to be identified with the profile or have their face tied to this AirBNB profile. That is a *huge* red flag.
I use Instant Book and have about 200 visits to the home over the past two years. Only a very small number were shady and suspicious; of those, perhaps two or three were profiles of a cartoon or a picture of a building was shown, or something like that.
Of the no-profile pic people, only two or three people who had ulterior motives and did in fact cause problems during their stay. I investigated selecting the option to only accept reservations from verified profile pics, but it was buried pretty far down in the settings and seemed like it could backfire with people who legitimately just hadn't uploaded a pic of themselves. In the end, if problems arise, I just give a bad review so future hosts will know to beware.