I like a lot how discourse inserts images and how the lightbox displays them.
But we - as a photography forum- miss one feature: being able to display a minuature of the first image in a post to the left of the title of the post in the categories view.
Whether it is showed or not should be selectable in a category basis.
We are seeking for something similar to this : Flora y fauna
May be it should be implemented as an addon or plugin to discourse.