Lyft provides you a picture of the Vehicle and the driver. It really improves the customer experience - I'm always interested in who my next driver will be - and choose lyft just because of this feature.
I don't really understand the need for pictures of drivers, personally (except maybe as a means of authentication/identification, but once you go past race/sex/age/etc., I'm really bad at IDing people from faces); I judge people based on a lot of things, but generally not things visible in photos. I'd probably judge someone as a driver based on type of car and condition of car more than anything else; DMV driving record, whether the person is local, etc. would be even more desirable.