You show your card, and they copy some info from it and give you a voucher. You get about 5 - 10 minutes with at least 2 characters from the "Fab Five" - Mickey, Donald, Goofy, Pluto and Minnie. We saw Pluto and Mickey. They take the pictures and save them to a photopass card, which you take up to the camera shop outside of Spaceship Earth. You get to pick one photo for free (with your voucher). They added some graphics (Mickey's and Pluto's signatures) to our photo, but you can have the photo just plain if you like. And, of course, you can order more if you want, sicne they are all on photopass.
DSis and I thought it was great, but we were the only all adult group there (we are 30 & 32).