So here: https://maps.app.goo.gl/ZsaZBNrKfc1PQVhC8
Loading relates to goods, not people with their luggage, and in any event loading is only permitted from 10 am till 4 pm, however the sign is obviously inadequate because this is a stopping prohibition, meaning that you are not allowed to stop the car to look at the sign. This means that the sign must be visible and must be facing traffic, so that you can read it without stopping. As the sign is facing the wrong way it is inadequate, and that is a straightforward ground for making representations.
Here is a draft:
Dear Transport for London,
While I accept I stopped in a red route bay, there was no sign visible informing drivers of the restrictions applicable in this bay, it follows that the alleged contravention did not occur.
Yours faithfully,
Send this via https://tfl.gov.uk/modes/driving/challenge-a-pcn and make sure to keep a screenshot of the confirmation page.
In parallel, don't forget to ask for the video as well.