This is what I call a jigsaw puzzle miter joint frame. We will use stack cutting to make two frames mixing the parts to get this two tone effect.
The frame will hold a 4" X 6" picture. I am using 1/8" Plexiglas instead of glass.
You will need two 1/2" thick boards of different contrasting colors. I used walnut and maple. You will also need a 1/4" thick board for the back frame.
Wrap the two boards together with blue painters tape. Make sure they are squared up and covered well with the tape. You don't want the boards to come apart while cutting.
Cut out the center of the stack.
For the miters you need to use a thin blade. I used the Flying Dutchman Superior Puzzle blade. You could also use a #2/0 blade. You just need the thinnest kerf you can get so the pieces fit snug.
As you cut the miters re-tape the corners so they don't come apart while you cut.
Dissemble the parts making sure you keep the pieces in the proper order and all facing up.