I think that the editor should base the decision about which image template to use on the image itself. The idea here is to avoid triggering people who might find the image very upsetting, or (in the case of other hypothetical images) to avoid getting someone in trouble by exposing that user to images that are illegal for the user to see. Someone just browsing through Fanlore might not have read (and indeed might never read) your Star Trek story, and so couldn't know that the sex was consensual, just going by the image itself.

It's a good question, and we'll edit the policy to make that clear.