That's terrific, especially her whole affect as she relaxes as if it was a heavenly bath. Her expression is priceless and the pose shows pure contentment. The punch came out looking really good too, perhaps good enough to drink if not for the occupant. ("Bartender, there's a pony in my drink!" "Okay, you're cut off.")
The idea of "Mane Six Mix" sounds pretty good to me. Actually, I'd be surprised if people haven't already created drinks based on most of the ponies.