I don't get the point of this mod. Why not just use the attachment mod's thumbnail feature? It does the same thing. Besides...shrinking the image does not shrink the size of the image file...so...even though the dimensions are small...the full size is loaded.
Perhaps the objective is to provide a means to reduce images when GD Graphics Library is not available (I assume this is what is used to produce thumnails).
For all of you who all this does it make it so the pictures are clickable, you must go to the "Special Categories" section of "Extensions". If you scroll to the bottom you can input a maximum width and height.
It works fine for me, however the download times number goes up with every page load, not really a problem mind you, I just like to keep track of how many times certain attachments are downloaded.
I made all the modifications and tested it and found that when I click on "Preview", it actually does resize the picture, but when I submit it and then view my post, it's not resized at all.
I noticed that the html tags for HEIGHT and WIDTH are there in the preview mode, but gone in the regular view mode.