First off, welcome to the forum, @tomfido!
I don’t think this is the kind of multiple-species observation that Jean Philippe is talking about. If you have a photo of five different insects on a flower, there is no problem at all duplicating that observation and identifying each species present, although it can be helpful to crop it and put a cropped photo of each species as the first photo of each relevant observation in turn. You can also add observation fields to make explicit the interactions, such as flower visitors. That would be the best approach, and is to be encouraged for examples like:
The sorts of multiple species observations I think Jean Philippe is talking about are usually from new users, who have gone out and taken a photo of, say, a daisy, an oak, a squirrel and a beetle, and upload them all as a single observation. Those need to be split into different observations to be useful and identifiable.