Mirror with no instructions..how do I mount this?

We are trying to mount this 30 x 30 inch mirror above a dresser in our nursery, but the mirror came with no hardware nor instructions other than, don’t use a wire on the back to mount. I believe this is technically a round bathroom mirror. We have never seen a backing like this. Anyone have any clue what these are called and how we can safely secure the mirror to the wall? Second pic is of one of the bracket like pieces. TIA!!