Comment HTML Formatting Buttons and allowing image links

A few questions about the Comment HTML Formatting Buttons plugin with respect to allowing images.

At the opening of htmp_buttons.php (the file that seems to drive the comment formatting buttons) is a variable

var $allow_img = FALSE;

I assume this has an associated global that can be defined in the config file? For testing however, I’ve just set to TRUE.

This then does seem to add an additional button to add images, however, the behavior I expect does not seem to happen. When the button is selected it simply adds the following BB tags

[img][/img]

to the comment text area.

I’m wondering if this is the expected behavior, how a user is supposed to use this feature?

My expectations are that it would, prior to adding tags, fire a JS prompt with an imput requesting the URL to the image followed by the same for an “alt” tag.

Am I off base with this assumption? If so, could someone please explain how this is to be used?

Thanks