Trixie looks beautiful in that outfit. I love her expression as well as the color scheme of her dress. The design of the moons on her dress as well as her hat and boots (I guess they're boots since they're on all four of her legs) is simple yet amazing. I also like the small diamond that holds her dress together similar to the gem that does the same thing with her cape. I'll bet Trixie will get her fair share of ponies asking her to dance when she arrives at The Gala (and her arrival will be Great and Powerful I'm sure).