Just a guess:
- vertical “stick” taped to bottom side of the pre-cut circle or medallion
- horizontal stick taped to the top side
- engraving and cut jig on the right
Cut the jig and remove the center.
Engrave the text on one side of circular medallion.
Flip medallion along vertical axis and remove the vertical stick on the top.
Engrave the text on the other side.
i think what @dan was referring to with the circles, was that if you try to engrave on both sides of a pre-cut circle without indexing it in some way, the text might be rotated away from where you want it placed on the medallion on the back side