Looks like MLB The Show are one of the first to use Vine as an advertising media space, by creating special animations of baseball plays for their favorite "baseball influencers" as well as fans of the show. They're like animated baseball cards.
MLB The Show is currently releasing video baseball cards utilizing Vine, which is the first of its kind.
They surprised a number of individuals on Twitter with their own custom created baseball card, which features a game version of themselves sporting their favorite team. The list included a wide range of gaming and baseball influencers as well as huge advocates of MLB The Show.