"High Definition mess"
1. Literally: When formerly hot celebrities are exposed in all their true wrinkled glory through high definition technology.
2. Or in any situation: a giant mess in which fucked-ness is so embedded in every detail that it will never be fixed.
Miranda- "Brad Pitt is still so hot."
Amy- "Have you seen him in Moneyball? He's a HD mess."
Just chill out for now or don't worry about events over which you have no control. This comes from the advice given next to flights in departures, 'relax and shop' before a gate is confirmed. It describes what one should do in purgatory before events or decisions which could go either way, good or bad.
John: I'm really worried about those test results.
Marsha: Well, there's nothing you can do now, just relax and shop.