Sent off a message to the seller of the dog collar I received yesterday, and got a couple of very quick responses. Sorry, the box is still the old one, and it says 200 m range, but never mind, it's really 800. And yes, here are the instructions:
Yes, what they sent were exactly these JPEGs. That certainly does nothing to improve my impressions. It also doesn't explain the neon tube, but Michael Hughes and Peter Jeremy independently worked it out: connect it across the connectors on the collar and it will show whether it's working or not.