Observations with the same photo where permission is given are OK on iNaturalist. Since an observation records a person’s encounter, and there were two people there, these wouldn’t be considered “true” duplicates by iNaturalist’s definition. There is no copyright infringement because permission was granted, so no curator action needs to be taken.
hi - welcome to the forum! The request for a shared observation feature hasn’t been voted down or closed by staff as an unwanted feature. The topic is still open for voting and discussion.