IMO, contravention did not occur.
OP, to give you the full prohibition...
85Prohibition of double parking etc.
(1)In a special enforcement area a vehicle must not be parked on the carriageway in such a way that no part of the vehicle is within 50 centimetres of the edge of the carriageway.
So, quite clearly what you did was not the nuisance agsinst which the prohibition is targeted.
Anyway, from what I can see, you were parked on the carriageway adjacent to its edge right next to a vehicle crossover which gives access to a parking area off the road.
The DYL are actually marked on the footway, not a carriageway at right-angles to the main road.
Others will have views.