The uniform looks "ok". Some like it, but most have a below average opinion of it.
Delta picked some guy that makes dresses for runway models to design a uniform for flight attendants of all shapes and sizes that have to wear it for 12-14 hours per day including lots of movement, crew rest, walking etc...
Paying Zac Posen hundreds of thousands of dollars (some rumors are a little over a million but...) was a complete waste of money.
Bet as we all know, Delta loves to was money on the red carpet and pinch every penny out of you elsewhere.