Hinge for the background picture

Two-sided adhesive carpeting tape.

Normal adhesive packing tape sticky side upwards.

Fold the tape upwards and stick it to itself in order
to make a durable edge.

Make the other edge the same way.

Take more 2-sided adhesive carpeting tape.

Use the light from a window to see where the plate ends.

Stick the original edge of the 2-sided adhesive carpeting
tape where the plate ends and the edge that you have cut to the
other direction. That way it doesn't matter if you haven't cut

Cut away the extra pieces but don't cut the packing tape.

Peel just a little corner.

Fit the picture exactly and then stick it to that corner.

Peel one edge and attach the picture straight to that edge.
Now it's in the right position.

Finish the edges with the back of your finger nail.

If the picture doesn't cover the whole adhesive taped area
you can rub off the sticky glue with your finger.