If you're short of bandwidth or limited by a quota, uBlock Origin can be toggled easily between allowing or blocking all images. It's what I use to make my 750MiB per month GSM/4G connection last.
Curious if it replace it with an empty block that takes up the same space so the layout doesn't change?
There is an option to block media elements larger than a set size[1]. When a media element is blocked through this setting, the element is replaced with a click-to-load widget, so the layout shouldn't change with this option.