Way too high. Usually the center of the picture is about 5' off the floor.

To high in fact in a dining room the art can even be hung a bit lower since it is viewed while seated. That little shelf seems a bit silly there why not look for a nother piece of wall art

Artwork should always be hung considering the height at which it is to be enjoyed. In a dining room you will be enjoying it seated so I would suggest you hang it about 3- 4 inches lower than it is now. Additional art in that room, should be hung at the same height so that the tops of all the art are at the same eye level. These are just guidelines for uniformity or course each home and one's taste is unique. As is the height of the homeowner. Also consider that art is the "jewelry" of your home so it's last thing to decorate with. If you add curtain panels to a window the art will need to be re-centered between the panels and the wall to the left or right. If you are unsure use the removable 3M hooks to try different things as they won't mark you wall when used correctly. I've noticed that men tend to hang art higher than women because they are usually taller? Has anyone else noticed this? Compromise is always good - lol :-)

Tell him to put up some curtains first....Then add the artwork(lower).