Hi @warnernature, welcome to the forum! This came in as a feature request, but because it’s already possible to add photos to journal posts, I moved it to #general.
You have to use HTML currently to add photos to journal posts. For example, if the photo is located at https://static.inaturalist.org/photos/47111201/large.jpg , the code would be:
<img src="https://static.inaturalist.org/photos/47111201/large.jpg">
That means the photo needs to be uploaded somewhere already, like in an iNaturalist observation or an image hosting website, before you can add it to your journal post.
There are open requests to make formatting comments and journal posts more user friendly. In the meantime, here are some more simple HTML tips for use on iNaturalist: https://forum.inaturalist.org/t/useful-html-tags-for-inaturalist-comments-and-other-text/6198