Hasbro has hopped on Snapchat with a new filter titled simply "Friendship is Magic". Right now all it does is add the effect you see up above to whatever image you use. There wasn't any kind of official announcement for this, so I have no idea if more options will eventually be available. For now, I guess you just need to stick to Twilight and Pinkie!
Thanks to PrincessLuna101 and Perfectly Imperfect for the heads up.