From what I understand, LE originally concluded Ross posted that image but once the full context was known, it was actually one of the women he was messaging that posted it. It's never been clear to me if he had previous conversations with the woman who posted it.
I don't think whether or not they had been in touch before has been brought up. I doubt it. I wish we and the jury could see the entire record of all online and phone activity by RH, even just one day's worth . I think that record would be very revealing about how little invested RH seemed to be in any of his dozens and dozens and dozens of online targets and conquests, and equally revealing about what seems to be an extremely short attention span for anything.