I am very new to this Secret Pal thing and this may be totally erroneous information since last month was my first one.
What I saw last month was that people would post pictures of the received gift with a thank you on the swap section. That way you are certain that it was received and everyone can enjoy your gift with you.
I always photograph anything I put into the mail (for a lot of reasons) and I was glad I did. My secret pal didn't post anything although I got a PM saying it was received. I went ahead and posted what I sent to her so everyone could see what she got from me.