Currently, an attached image to a Jira comment is easily resizable (and looks nice at all sizes) so long as it is not a thumbnail. When you make an image in a Jira comment a thumbnail, it no longer looks nice at larger sizes. The image is also defaulting to not a thumbnail.

This suggestion is to (a) default Jira-comment images to thumbnails and (b) make thumbnails easily resizable in Jira comments (and make them look nice at the larger sizes)

 

The cloud version of part (a) of this suggestion is JRACLOUD-76643.