Another place, considering their depreciated nature anyway, is to create a draft guide, and upload your images there. You can then insert them into your comment using the HTML code <img src=“picture URL” width=“250px”>
eg
<img src=“https://static.inaturalist.org/photos/48653435/original.jpg” width=“250px”>
Or get more sophisticated and make the thumbnail image a link to the fullsize version:
<a href=“picture URL”><img src=“picture URL” width=“250px”></a>