string of pearls is an easy-care succulent plant. It looks stunning in hanging baskets, trailing down. It is drought tolerant so you don’t need to water frequently, once in every other week would be enough.
(Hummm, neat idea, but uncertain on photos wrapping around the corner. The frames could meet up on the edge, but think the frames still might be best if they met in the corner but that each wall had its own photo frame.