Hello Milan, thank you for this great plugin.
I am using it with PrettyPhoto and it is working well.
I have added the rel attribute of wp-prettyphoto[bbPressAttachment] so that the attachment images show as a gallery.
This works well, but includes all attachments of all replies to the topic in the slideshow.
I wanted to know whether the rel attribute could be dynamic so that it became wp-prettyphoto[the ID of post], or wp-prettyphoto for example, so that the attached images of any one reply would be a separate slideshow.