My concern over the picture in question is that it looks like the woman doesn't know it's being taken, and when consent was questioned, the poster of the picture left the the answer vague, and brushed it off.
If having consent when posting nude pictures was important to the community, the poster would not have left it open for interpretation.
They probably would have been offended at the suggestion of posting without consent, but this was just blown off as joke.
I honestly cannot see how anyone cannot see that picture as potentially non consensual, regardless of their feelings about how important or not it is that nude/sexual pictures don't get posted without consent.
TGR asked the poster if it was consensual and they said it was.
Regardless, the response was left unchallenged for a year, so nobody was particularly concerned. That speaks for the community as a whole.