Following a few comments here is in photographs how we attached this picture to the wall.
We have a couple of pictures like this. We found them at a second hand stall. This one is my favourite, I love that Otis can see the farm animals.
We use Command Picture Hanging Strips. They are temporary so you can remove the strips from the wall and your picture without any damage. This is perfect for a toddler's room where you might want to move the pictures frequently.
One strip goes on the picture and one on the wall. The reason this works well for this picture is because the strip is placed on the picture backing, not on the wooden frame as seen here.
When you match up the two strips and click them into place...
this fame sits flat against the wall. Otis has so far been unable to remove it from the wall. Although he tries he cannot get his fingers behind the picture to pull it off. If he was successful I would add a few more strips. I have used the strips on other pictures and they are stonger than they look.
I'm happy for him to touch and explore the picture. There is no glass cover to be concerned about. I wonder about it's origin. Anyone recognise the style?