Image macro
Appearance
A phrase to describe images often used on USENET before the existence of website forums. An image macro is a image with a phrase superimposed over it. Often used in flame wars and a fundamental feature of gif wars. An image macro usually expresses disdain towards a previous poster or a discussion thread.
If overused, their impact can be diminished.
(Can someone who was on the internet before websites existed check this for accuracy?)