While it's not technically called a "baseball card" if the person in question doesn't play baseball, we'll call it that for the sake of this article since it's made by Topps and will be included in the 2012 summer series of their baseball trading cards.
Upton, the voluptuous blonde model who shot to superstardom after appearing in a racy Carl's Jr. ad, is also a big name over at Sports Illustrated, which is what landed her the trading card honor. 19-year old Upton will no doubt have hormonal males everywhere vying for the decks, which could prove to be an interesting marketing move on Topps' part; sales have waned in recent years due to advances in technology. In short, kids are going digital, and trading cards are a bit antiquated unless you're a hardcore collector (which breaks my heart, as I loved baseball cards as a kid and had two huge binders full of them).
The new series debuts in July and is modeled after the 1800's baseball cards, which were produced by Allen and Ginter--a tobacco manufacturer--and placed into cigarette packs. The set is well-known for including non-baseball players on the cards, and this latest venture by Topps will follow in their footsteps, adding familiar sports faces Bobby Knight and Arnold Palmer this year.
And now, for your viewing enjoyment, Kate's Carl's Jr. ad. It straddles the line as far as being safe for work, so use discretion. Take that in whatever sense you want.