I'd like tor request an add-on to block the dowloading of images by working like this:

Block all images from downloading.
Display images if in cache.
Display image placeholder if not downloaded.
Click placeholder to download image.
Options to allow/block images based on download size.
Whitelist toggle.

The main reason for the add-on is for using an ISP that charges/throttles based on bandwidth.
I want the option to choose which images to download.