I hate to keep hanging around like a creeper, but I couldn't resist. EqD! Your art is amazing enough that people liked it and sent it to EqD! Wow... People can finally see what insanity lies within the confines of my mind for once!
Well, the way I see it, after the Alicorn Amulet incident, Trixie lost everything again, but she gained a new lease on life. She shuns all but her own natural magic skills, and works her tail off to improve, building on the skills she already had and studying like crazy to gain new ones. Slowly, bit by bit, she painstakingly rebuilds her reputation from the ashes of her past failure. Trixie the White is the result of all that hard work. Still the same charismatic, confident, highly magnetic mare she's always been, but without the crutch of lies.
She was successful at freeing herself of her personal demons, which in turn helped her become a much better performer, and a much more powerful unicorn.
Seriously. If I hadn't already devoted all my hugs to Trixie, I swear, you'd get at least half of them, PB. This beauty has brought my faith in humanity to a cool 40% (up from 20% from all the bullcrap happening lately, Zimmerman trial, the royal baby thing, etc.)
This is how I imagine Trixie would have reinvented her image after the Alicorn Amulet incident. Still her boastful self outwardly, but humble on the inside, with newfound magical knowledge and ability. She's the not the Great and Powerful Trixie anymore.