Well in the episode this is based off: mystery on the friendship express, Twilight played Sherlock and Pinkie played Watson( although this was the original classic versions and not based on the RDJ movies, where Pinkie makes sense. I imagine Trixie as Twilight's Irene Adler, and Discord as her Moriarty.
T.S.: So your free this evening? P.P.: Absolutely. T.S.: Dinner? P.P.: Wonderful. T.S.: The Gala? P.P.: My favorite... T.S.: It's my coronation. P.P.:....Not available. T.S.: It's happening, Pinkie...whether you like it or not. 8:30 The Gala, wear a jacket. P.P.: You wear a jacket.
On the spot I thought that would be this version of Holmes. Great rendition in my opinion. Beautifully made. She got the look, the randomness but not Holmes' brain. Bah. I still love her. Brings a smile in a second.