An acronym created by a group of friends to laugh at, as they heard idiots in the hall say "lol" and "rofl".
HDTMYF = How Does That Make You Feel?!
Person 1: "This is such bull. My professor is a total jackass who deprived me of my A!"
Person 2: "hdtmyf?"
Person 1: "Dude really?"
Person 2: *nods*
Person 1: *looks down defeated* "Makes me feel like a complete nerd."
A portmanteau of HDMI(High-Definition Multimedia Interface) and TMI (too much information).
When an HD image or video is in such detail that it exposes unpleasant details, usually wrinkles and/or acne, that would normally only be visible in extreme closeup.
"This is not a flattering image, HDTMI no amount of makeup would cover that up. The camera sees all."