Hi Sirje
There are probably a number of reasons that this could have happened including:
1. The person who you sent the photo to could be under contract to only sign photos that they send out and not anyone elses.
2. The photos could have been mixed up with someone else's photo, and they've accidently sent you someone else's photo instead of yours.
3. The photo you sent could have been damaged in the mail, so the celebrity was kind enough to send you a different photo.
They're the three reasons I can think of now. However, there are probably could be other reasons too. I hope you like the photo that you received though
nowandagain [rockon]