photo
Hi!
Maybe I'm wrong because I had my OD four years ago but the full-length photo must have been postcard size. And yes, I had to redo mine before my final interview. Fortunately, I had time because I had to go for 2 p.m. for my interview. I was so lucky because my new photo in my new suit was much better! The photographer lady was quite old fashioned and very professional. She tried to do her best.
I think they ask for natural photo (so not business attire) as well. I just read it on pprune before and my friends who were hired in 2008 had to send one as well. (Full-length, only you on the picture, jeans or skirt, hair up or down, so not formal.)
Don't worry, they will tell you exactly what they want. It takes only one hour to have it done.
Good luck!