Hello, I picked up this piece a while back and am a bit confused.
It appears to be two German pre-printed postcards dating to 1900 or after that are connected. The inside postcard has an address and is cancelled, so was sent through the mail. The attached postcard (on the other side of the blank section in the first image) has no address and is not cancelled. I am not certain what this is or how it went through the mail. Thanks for your help.