Main disconnect in sub panel

The feed for this sub panel was from a 50 amp breaker in the main. I’ve never seen power brought into a sub like this before with a main disconnect and the wiring at the main lugs. I believe it’s ok but I wanted to run it under other eyes. They had commingled grounds and neutrals in the sub but that’s another matter. Thank you everyone.

If you look at the diagram on the label you’ll see that it’s a split bus panel. The jumper is energizing both sections of bus.

That is an odd bird. I would like to see a wider angle showing the whole panel. I’d like to see where the conductors behind the lugs are going. Certainly, the jumpers with the electrical tape insulation are improper. A shot of the label on the left would be nice too. From what I can see of the label, it looks like someone did a half-assed conversion of a split-bus.

Ok thanks guys. It already needs to be repaired because of the mixed grounds and neutrals so that gives me another reason