harrrrrry I've identified the issue and put a fix in place for this.
I've also edited the OP in the thread you linked, so that the image now displays.
A little more context around the issue:
When an image is uploaded to the community, it is renamed and stored as something like
date-randomnumber - unfortunately in this case, the random number generated matched the format of a potentially valid credit card number.
The solution, in this case, was to refine the way the filters look for card numbers. I'll also follow up in the medium term about changing how the filenames are generated, to ensure they don't generate a name which might be caught in the filtering.