I took this pic when I was in Japan. I have no idea which geisha was real and which was not. I post the pic and found answer from the comments:

bib/smr says: a tourist ;)

Judith Montana says: She's a tourist. She's wearing white eri, the wareshinobu hairstyle (it should be ofuku) and kanzashi for young maiko. It doesn't match. And Her make-up is pretty bad.

bib/smr says: no, the hairstyle is right for a first year maiko who wear that kind of dandling kanzashi (hair ornament).

what makes it clear that it is a trourist, is the fact that that person wears a wig (one can notice it behind her ear) and of course like you sad it the make up is pretty bad.

and like you pointed it out Judith Montana, the white eri (collar) indicates that it is a senior maiko which isn't the case here and totally wrong considering the hair ornements and hairstyle ^__^

all this little things distinguish the real maiko from the fake maikos.