This appears to be implemented, although I don’t know the markup for it.
Ability to disable images in comments.
Markup is:
That doesn’t work for me. I can’t tell what the problem is.
You may need to put some text in the square brackets. I know this works, ’cause I lifted it from an old comment of mine:
Still doesn’t work. It might be a problem with the site hosting the images. I’ll have to experiment.
What image URL are you trying to use?
Got it.
Markup: 
This appears to be implemented, although I don’t know the markup for it.
Ability to disable images in comments.
Markup is:
That doesn’t work for me. I can’t tell what the problem is.
You may need to put some text in the square brackets. I know this works, ’cause I lifted it from an old comment of mine:
Still doesn’t work. It might be a problem with the site hosting the images. I’ll have to experiment.
What image URL are you trying to use?
Got it.
Markup: 