In this discussion I am assuming that this is not a separate structure on another structure's service.

I think that one of the first questions to ask when looking at an electrical system is: Which piece is the service equipment? Either this panel is the service or it is not.

If it is the service, then neutral and the ground should be bonded, with a screw, strap, conductor, or some other approved means. But if it is the service, presumably there is no disconnecting means upstream of it, or that disconnect, or something upstream of it, would be the service, and we have the problem of more than six throws to turn off all power.

If it is not the service, then there should be both a ground conductor and a neutral conductor coming into the box, and grounds and neutrals should be kept separate.

Unless there is a ground conductor coming in from the enclosure on the left, from what I can tell from the picture, it looks as if there is a problem.

- BOB