David where are you seeing a GEC? Looks like this is the service disconnect(s) and the circuit with the split neutral is a feeder. If it is the service disconnect(s) then the neutral must be bonded to the enclosure. A wider camera shot of the entire installation would be helpful.
You’re right, Robert. I don’t see many main service panels that are that small, in residential applications (if indeed it is residential). It would be helpful to know what equipment it is serving. I saw the green ground wire and thought they were using it as a GEC, as is so often the case with shade-tree electricians.