Hello ^^
In order to be able to let photos to be saved by the receiver. Please follow this simple tutorial that I will provide.
First, you have to check if saving attachment options is allowed. You can check this by clicking on the arrow near the " Write note option" Click on the arrow. Scroll down to the last option then see if the " Allow saving option" is Yes. Because the default option will be set to "No"
Second, you just have to send the photo and they will be able to save photos you send with the swapnote.