Try examining the back

While Kasha had gotten a good look at the front, she decided to examine the back before doing anything else. So, she lifted the frame, looking at the back from below. There were some runes carved on the back, but Kasha did no have the magical expertise to try to interpret them. She could try to scratch them out, and maybe that would break whatever spell was on the frame and free the key, but it could also seal the key inside or even spring a trap.

And as Kasha moved the frame to get a better look at the runes, she heard something rustling through grass. Confused, she looked back at the picture and saw that the key had moved from its place inside the picture.

Odd.