Also have you checked Elegant themes/divi ?
I think discourse have images being shrinked into body and Expands while clicked
Can you implement the same Auto zoom behavior in discourse ? think of it in this way, I posted 20 images for a post, so if this Auto Zoom is implemented, if discourse system detects i posted 20 images back to back, discourse can auto zoom with background lights being turned off, so it will feel like someone has black theme activated while the Auto zoom image featured is being activated… would be great if we have this kind of futuristic setting.
And unnecessary elements can be removed, for example, the download button, right click on image and you see an option “Save image as” and everyone knows it will download the image and i am not sure how many people are downloading images from communities while 95% of the times images are for illustrative purpose so my suggestion is discourse need to start giving more importance to Immersion where discourse automates immersion for images to take full screen area of the display and less importance for file names/download button.
Also there seems to be original image, discourse is making us to believe that we are in 2000 where internet bandwidth is Expensive, images takes less than 10 mb and most users wont care about losing 10 mb so always use original image and even if you were to compress, be less aggressive(less color reductions).