First Matthew carefully selected which toys he wanted to take photos of, then they arranged them and took the photos. Next they edited them with different colour effects, then printed and trimmed them, and put them in the frame. Plenty there to engage small people.
We happened to have this slide puzzle picture frame knocking about (and that works really well for added interactivity) - but any frame would do and they would also make good cards.
We have it up in our kitchen but I'm thinking of doing something similar for Matthew's bedroom because he loves it so much.