The pictures seem to be making claims after the fact of what they show
If you allege someone punched you in face and you get police report at the time and then get them to document your injuries that's proof.
Showing a photo of an old injury and retrospectively assigning responsibility for that to someone else, really isn't a very strong piece of evidence legally. At least in this country. Brazil may be different but given the story has been running for a good while now, I suspect it might be the same.
Unless there are police reports made the time that substantiate the injuries from the photos then i would doubt they would even be admissible in any criminal trial. Civil court (or Brazilian equivalent) is different story.
Hypothetically in the Greenwood case had that gone to trial, the cut lip picture would not have been seen by the jury or permitted in court by a judge for the same reason as it wouldn't meet threshold to be considered evidence.
The photos really aren't evidence without police reports being made on the day they were taken by the police themselves