That's a feminine pads pouch. You can put up to 4 pads in it:
I sewed that as a gift for my sister KiKou.
It's really convenient as you can keep that in your handbag without any risk of having anybody guessing what's inside!
Here the pictures of the back:
I love the fabrics (from JoAnn's) I used.
I even did the bias strip myself. It was new for me!
I even did the bias strip myself. It was new for me!