Ryan actually covered the set pretty well in a post he did recently so I'm not sure I have a whole lot to add here. Of the 81 cards in the set, 72 of them are "regular" player cards and the remaining nine are a subset called "Off Shot" which features candid photos.
It is an interesting group that BBM selected to be in the set. There's a handful of guys who had long careers in Japan - Leron and Leon Lee, Boomer Wells, Tuffy Rhodes, Alex Cabrera, Bobby Rose - and a group of players known better for their MLB careers who only played in Japan for one or two seasons - Davey Johnson, Bob Horner, Larry Parrish, Julio Franco, Cecil Fielder. Most of the players fall into between. As is typical for a BBM historic set, most of the players included were active from the 1970's and later, although there's a couple guys from the 1960's. Many of the pre-1991 players have not appeared on a BBM card before. The set also includes a couple of Taiwanese players in addition to the Westerners.
As with any set like this, you start to look at it and think about the guys that didn't make the set. None of the Nisei players from the 1950's (like Wally Yonamine) made the set, nor did any of the handful of Americans to play in the pre-war era (like Harris McGalliard). It would have been interesting if either of the American Baseball Hall of Famers who had played in Japan (Larry Doby and Rich Gossage) had been included (especially Gossage as I believe there are no Japanese cards of him at all). I don't think there are any Koreans in the set - Jong-Beom Lee, who played four years with Chunichi in the late 90's might have been a good choice, as well as Dae-Sung Koo who spent a couple years with Orix. Legendary Cuban slugger Omar Linares would have also be a good choice. I think the biggest omission, however, was Bobby Marcano, who spent 11 years with Hankyu and Yakult in the 1970's and 1980's.
Here's some sample cards (Ryan has almost all of them scanned with his post and Jambalaya as usual has them as well):