I am not a photogenic person myself but basically OK with it. Say cheese and pray it'll be over quick, thats basically it.

My gf however is absolutely phobic about it. She will absolutely refuse to have her photo taken. She has made only very few exceptions when she was willing to take her own photo to send it to me but if anyone else tries she will panic. I remember the two of us visiting the xmas market in Hyde Park London and someone at the Ferrris wheel wanted to take her picture. But she flatly refused that and i had to quickly escort her past the menace.

In her case its most likely cause by a combination of self esteem and body dismorphics disorder. I am working on it together with her and I feel that perhaps we have been making some progress.