PCN - Loading Bay

I parked, or more accurately pulled into, a loading bay; my daughter got out to go and deliver AND collect an item across the street from the bay.  She returned within a few minutes as the item wasn't there and we drove off.

A week later I received a PCN from the local authority: "25J Parked in a loading place during restricted hours without loading".  The notice states my vehicle was observed from 12:35 to 12:39 and that the LA believes a contravention occurred.  The paperwork also shows two photos of my car time stamped 12:39:55 and 12:39:59 (i.e. my time of departure).

I do not dispute being there (obviously!), but I was there for the purpose of delivery/collection - albeit not for commercial reasons (I'm not a delivery driver!) - and I personally did not leave the vehicle, my daughter did (she's an adult), and throughout the time I was in the bay, my engine was running (I knew I wasn't 'parked' in other words).

There are some roadworks taking place in one third of the bay, it usually has three spaces but was reduced to two with the area cordoned off with yellow and white 'cones' (not actually cones - they look like planks with yellow posts).I am not sure if this is relevant but will be returning to the area to take some photos of my own.

My questions:

1. Is it worth appealing this based on the fact that I obviously wasn't 'parked' given I was in my car and the engine was running the whole time and I was in fact delivering and collecting something albeit the item to be collected was not ready and therefore my daughter returned to the car without it?

2. I will be requesting sight of the video recording as I think the fact that my daughter got out of the car and returned to it within four minutes is evidence of collection/delivery and not parking - would this be valid? (I am aware of the definitions of loading and collection/delivery from the case law.)

3. Is the fact that I was there for 4 minutes in total not sufficient evidence that I was not contravening use of the bay - after all, had I been parked to shop it would have taken more than 4 minutes and I would have got out of the car! 

Lastly, the ticket was not issued by a CEO - it was issued by camera, and as far as I am aware there are no signs indicating cameras are in use in the area (I would still have stopped there as I thought I was acting legitimately even if I had known there were cameras) - again, I will double check this and take photos if necessary.

Thank you in advance for your help.