The other side is empty. Looks to be missing the ring that anchors the photo.
On the side of the photo you can see tiny little screws used to anchor the photo. These are old and original. See second to last photo.
The base of the locket is gold filled as you can see from the interior photos. The engraved outside is most likely "gold shell" which is a thin panel of gold placed over a more substantial gold filled base. The front panel has a Town Scene etched. There are a couple of lines that may be scratches. See Last Photo between my finger. I never even noticed them before. The etched panels are in great condition. The back panel has a floral design on it. This is a good sized locket measuring approx. The Locket is antique dating to c.