In the background is a perfectly normal narrow lock. In front a horse is towing a boat away from the lock - except that its not a narrowboat. It looks more like a half-size Yorkshire Keel.
Judging by the marks around it, the boat has been spliced in from elsewhere, by a postcard publisher who didn't know the difference!
Inspired by this I have produced a couple more pictures showing boats in unlikely locations:
The QE2 takes a detour from Southampton to visit North Wales.
The Tuesday Night Club's most adventurous tidal trip to date!