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.
The creation of these intricate cards included an artist who designed the player, based off the likeness of their Twitter profile picture, and a gamer who played his way to their favorite Major League team
— MLB The Show (@MLBTheShow) March 28, 2013
— MLB The Show (@MLBTheShow) April 2, 2013